Engineering Education in India is passing through turbulent times. It is seen that since 2018 the... more Engineering Education in India is passing through turbulent times. It is seen that since 2018 the admissions for core branches such as Mechanical Engineering, Civil Engineering and Electrical Engineering is quite less compared to Computer Science and Engineering. Currently the supply of seats in engineering institutes exceeds the demand of seats. Institutions are unable to cope up with this sudden change and have reduced their intake in core branches or have altogether gone for closure of these branches over the last four years. Employability is one of the critical component for admissions. As the economy of nations boomed the demand for automation in manufacturing, use of Artificial Intelligence, machine learning has taken a quantum jump and the major IT companies over India had large hiring in these four years. In this work, the issues faced about employability of engineering graduates have been viewed from androgogical perspective and brainstorming was conducted with the stakeholders to arrive at the various issues ahead and the way to address the same. 26 measures were suggested by the various stakeholders be in alumni, parents, employers, training organizations, faculties. Google form was sent to the faculty members to solicit their opinion on the 26 points and Lickert scale of 1-5 rating was used to get the responses. Responses for 40 respondents (covering 6 Indian states) are analysed and the results are quite similar. 90% respondents agree that setting of new high tech labs and training for skill development, placement opportunities (Robotics, 3D Printing, Total Station QGIS, Revit, Sketch up), Functional MoUs with industries can help improve employability (with 70 % strongly agreeing). 90% respondents agree that finding out good sincere students (10-20%) i.e. segregation and grooming them in their field of interest, future plans can improve the knowledge, skill, attitude (KSA) for employment (with 50% strongly agreeing). 90% respondents agree that Self discipline /self management among students, attendance in college and responsibility in learning impact KSA of students (with 50% strongly agreeing). These responses are indicative that institutions need to align themselves in the changing times to make their students employable.
Biodiesels are substitute fuel sources that can be potential replacement to fossil fuels apart fr... more Biodiesels are substitute fuel sources that can be potential replacement to fossil fuels apart from being eco-friendly owing to their carbon-neutral nature. The energy originating from nature-based resources has a premium value due to its lowest environmental impact. The strategies that protect nature are grouped under a philosophy termed as ‘sustainability’. The biodiesel ought to give net energy acquire, have ecological advantages with financially serious, and producible in enormous amounts without diminishing food supplies. The proposed study examines potential of waste cooking oil as a source of bio-diesels by collecting samples of used cooking oil from the food outlets. The characteristics of producing bio-diesel from waste cooking oil are investigated from the point of view of utilizing it on a small batch mode of 5 to 10 litre. The chemistry of transesterification is investigated by adopting computational route to design a reactor and experimentally verifying the small-scale ...
Indian Railways has 45 workshops for maintenance of its fleet of rolling stock and out of them tw... more Indian Railways has 45 workshops for maintenance of its fleet of rolling stock and out of them two workshops catering to broad guage coach maintenance located in southern part of India have been studied for a period of five calendar years from 2007 till 2011 to analyse their output and the corresponding energy inputs. The various activities of the workshops viz. maintenance of coaches and other major works have been studied with respect to energy usage to arrive at a common unit of output for comparison. All the forms of energy input to these two workshops viz. Electricity supply from distribution companies, high speed diesel and LPG have been accounted for. The study finds that the energy requirement for undertaking the periodical overhauling activity per coach in both the workshops is showing a downward trend from a peak of 1110 kWh per coach during 2007 to less than 600 kWh as in 2011 which is gradual and consistent and correspondingly the total energy consumption and the power b...
Indian Railways (IR) has taken the lead and has planted Jatropha Curcas (Ratanjyot) saplings on a... more Indian Railways (IR) has taken the lead and has planted Jatropha Curcas (Ratanjyot) saplings on a massive scale on its vacant land as well as on either side of the tracks so that once these plants grow and start yielding fruits, the seeds can be used to extract oil which will be converted into Biodiesel (BD). This BD can be used as fuel in any diesel engine without much modification and as it is an environmentally friendly fuel its use is on the rise globally. For eg. France has made it mandatory to blend BD in Petroleum diesel (PD). US, Europe have taken lead and are manufacturing BD out of edible oils and using them extensively. BD is accepted as an alternate fuel by EPA of USA and India during the year 2005 has come out with an IS specification for BD (IS 15607:2005).
With the growing need of fuels for various activities like transportation and power generation th... more With the growing need of fuels for various activities like transportation and power generation the need for fuel has increased. Keeping this objective in mind we decided to pursue our project on production of biodiesel from algae. The reason we chose this as our project is because of ability to cultivate algae on large scale. After testing with other species of algae we chose Sargassum as it gave us 20-30% oil on 1 kg of algae. After the selection of the species we went to the Talpona beach in goa to search for the algae. We managed to collect 50kg of wet algae. After collecting the algae we dried the algae in the presence of sunlight. This was done to remove the water present in the algae. Once the drying processes was completed we moved to the grinding of the dried algae using a grinder. The powdered algae was boiled to obtain the oil. The oil that was obtained was used to generate biodiesel using the transesterification process in a biodiesel plant. We ran the biodiesel obtained ...
Energy conservation is the need of the hour in the world and more so in India, not only due to en... more Energy conservation is the need of the hour in the world and more so in India, not only due to energy imports and energy security concerns but also due to growing concerns of its environmental implications. Indian Railways (IR), the nations transport lifeline, is one of the nation’s major energy consumer and is passing through a difficult financial state due to high operating costs of which energy is one amongst them. Carriage Repair Workshops (CRWs) in IR undertake Periodical Overhauling (PoH) of coaches and are major consumers of energy in various forms, viz. petroleum diesel and electricity other than traction applications. CRWs were established in pre-independence era and over the years they have successfully implemented many state-of-the-art energy conservation measures (ECMs) using the latest technologies available globally. This study focuses on two CRWs both located in the south Indian state of Karnataka, one at north part of Karnataka, i.e. Hubli and the second one at Mysore which is in south Karnataka which are into PoH of coaches since several decades. The study delves into two aspects, viz. the drives which have promoted the ECM and the barriers which are impeding the implementation of ECM. Prioritization of barriers helps in focused attention and efforts in the process of overcoming them. The stakeholder’s perspective in any such prioritization scheme is essential and also rewarding. It is observed that the attrition rates in railways are very low and as such most of the employees have vast experience in the organization. To take advantage of the same, the main stakeholders (officers and engineers) of CRWs are interviewed and the various dimensions pertaining to drivers and barriers are collected by face-to-face interviews. Totally 124 respondents which comprise of one-third of the population including both the CRWs were involved in the study. Questionnaire was developed to rank the drivers and factor analysis approach was adopted to group the variables representing barriers into manageable factors and rank them. Forced ranking method was employed to rank the drivers and factor scores for prioritizing the barriers. Five-point Likert scale was used to measure the stakeholder’s perceptions regarding the 25 barrier dimensions in the factor analysis. The study revealed that topmost driver for ECM was “the drive by the workshop management” and the topmost barrier factor was “motivation of employees”. This underscores the need for policy reforms by IR for aggressive implementation of ECMs in CRWs for fruitful results in the years to come.
The paper describes fabrication of an E bike and its performance analysis by means of a dynamic m... more The paper describes fabrication of an E bike and its performance analysis by means of a dynamic model equipped with a suitable control for the management of the assisted drive of the e-bike. The main advantage of this approach consists of the opportunity to simulate different versions of performances, e-bikes characterized by different parameters (total mass, motor torque, top speeds under different load conditions) and different control strategies. The study also undertakes comparison of the e-bike with a regular e-bike. A test setup to see the difference between an e-bike with only assistance of a li-ion battery package and the second with the assistance of a li-ion battery pack along with supercapacitors. The basic approach to this study is to confirm the fact that the li-ion battery performance and range can be improved with the combination of super capacitors.
This paper undertakes study of two railway coach repair workshops located in South India involved... more This paper undertakes study of two railway coach repair workshops located in South India involved in periodical overhauling of broad gauge passenger coaches. The study takes into account the various activities in terms of maintenance of coaches and production of components the energy input for Carriage Repair Workshop Hubli (UBLS) and Central workshop, Mysore (MYSS). The specific energy consumption of larger workshop i.e. UBLS is comparatively less than the smaller one i.e. MYSS due to introduction and successful maintenance of many a energy conservation measures. Hence extended study was undertaken to analyse the drivers for energy efficiency and 82 respondents out of 235 supervisors were interviewed separately and their opinion on the rating of drivers for energy conservation (EC) were sought. The entire workshop supervisors were divided into four groups based on their functions viz. Electrical supervisors, Carriage Maintenance Supervisors, Production shop supervisors and lastly t...
The Loco, Carriage and Wagon Workshop at Hubli was established in 1885 under Southern Mahratta Ra... more The Loco, Carriage and Wagon Workshop at Hubli was established in 1885 under Southern Mahratta Railway (SMR) headquartered at Dharwar for maintenance of meter gauge locomotives, coaches and wagons. In 1919 Madras & Southern Mahratta Railway (MSMR) was formed and the workshop was brought under the jurisdiction of MSMR. The workshop continued with periodic overhauling activities of metre gauge rolling stock.
In order to facilitate use of vegetable oils as alternate fuels for CI engines their viscosity ne... more In order to facilitate use of vegetable oils as alternate fuels for CI engines their viscosity needs to be considerably reduced which can be carried out by various means. One of the most popular means of reducing the viscosity of the vegetable oils is by means of transesterification using an alcohol and a catalyst. In this work, efforts were carried out to successfully transesterify two non edible vegetable oils viz. Jatropha curcas oil and Pongemia Pinnata (Honge) oils by using Methyl alcohol and Potassium Hydroxide as the catalyst. The easiest procedure to manufacture biodiesel (base catalysed process) is described which includes determining of free fatty acid content of the oils. Presently various education and research institutions are carrying out the transesterification using trial and error methods which lead to wastage of oil, alcohol and requires considerable amount of time. By carrying out experiments using various combinations the correct procedure for transesterifying the vegetable oils giving the highest yield has been derived which is described in this paper. Even used cooking oils from houses, restaurants etc. can be used to manufacture biodiesel successfully.
Journal of Materials Research and Technology, 2020
Abstract Herein, we report a study on the performance of two well-known benzo [1,2-b:4,5-b']d... more Abstract Herein, we report a study on the performance of two well-known benzo [1,2-b:4,5-b']dithiophene (BDT) based donor-acceptor (D-A) copolymers for organic photodiode (OPD) application. Judicious material design motif via side-chain and acceptor unit alteration in both polymers resulted in the donor moieties namely, PBDTS-TDZ and PBDB-T, which were applied as active layers with fullerene derivative PC61BM in a bulk heterojunction OPD. Panchromatic light detection was afforded despite the molecular and structural changes in both polymers. Inverted OPD based on PBDB-T: PC61BM showed a comparatively broader photoresponse and better performance, with specific detectivity [EQE] of 3.749 × 1012 [62%] at a bias voltage of 2 V under red light illumination. This work entrenches the inter-dependent relationship existing between polymer structural design and their device performance for organic photodiode (OPD) application.
Abstract The energy storage prospects of organic molecule has recently rendered them as promising... more Abstract The energy storage prospects of organic molecule has recently rendered them as promising candidates for supercapacitors (SCs) applications. Herein, we report an investigation into the electrochemical and energy storage capability of two carbazole based monomer and dimer moieties, connected through mono (CBZ-1) and diacetylene (CBZ-2)-based linkages. Synthesized intermediates and final compounds were experimentally and theoretically characterized via spectral, scanning electron microscopy (SEM) analysis and density functional theory (DFT) calculations respectively. Excellent electrochemical properties were observed in an organic pseudo-capacitive-supercapacitor (SC) based on the carbazole derivatives, with the dimer (CBZ-2) functionalized with diacetylene showing a comparatively better capacitive and improved electrochemical characteristics (398 F.g-1 at a current density of 1 A.g-1) than the mono (CBZ-1) derivative.
Abstract The high trap-state density and low conductivity in compact TiO2 (c-TiO2) layer limits t... more Abstract The high trap-state density and low conductivity in compact TiO2 (c-TiO2) layer limits the power conversion efficiency (PCE) of organic-inorganic hybrid perovskite solar cells (HPSCs). Metal doping in c-TiO2 has been proven to be a successful strategy for enhancing the PCE of HPSCs. Herein, Zr is incorporated in the c-TiO2 layer with different doping concentrations, and its impact on the photovoltaic performance of methylammonium lead iodide (MAPbI3) HPSCs is investigated. Inclusion of Zr enhances the charge carrier collection at TiO2/perovskite junction as well as conductivity of TiO2 layer. It is demonstrated that Zr-doping reduces the dark current significantly by suppressing non-geminated recombinations, leakage path, and electron trap-states. As a result, the HPSCs with optimum Zr-doping (10 vol%) exhibits open-circuit voltage (VOC) of 1.076 V, short-circuit current density (JSC) of 23.57 mA cm−2, and PCE of 18.16% under one-sun illumination conditions. UV absorption confirms the increase in bandgap upon Zr-doping that leads to favorable band alignment with the perovskite layer. Further, the engineered solar cells are probed for current density-voltage (J-V) hysteresis, operational stability, leakage current, intensity-dependence behavior, and electrochemical impedance spectroscopy (EIS).
Engineering Education in India is passing through turbulent times. It is seen that since 2018 the... more Engineering Education in India is passing through turbulent times. It is seen that since 2018 the admissions for core branches such as Mechanical Engineering, Civil Engineering and Electrical Engineering is quite less compared to Computer Science and Engineering. Currently the supply of seats in engineering institutes exceeds the demand of seats. Institutions are unable to cope up with this sudden change and have reduced their intake in core branches or have altogether gone for closure of these branches over the last four years. Employability is one of the critical component for admissions. As the economy of nations boomed the demand for automation in manufacturing, use of Artificial Intelligence, machine learning has taken a quantum jump and the major IT companies over India had large hiring in these four years. In this work, the issues faced about employability of engineering graduates have been viewed from androgogical perspective and brainstorming was conducted with the stakeholders to arrive at the various issues ahead and the way to address the same. 26 measures were suggested by the various stakeholders be in alumni, parents, employers, training organizations, faculties. Google form was sent to the faculty members to solicit their opinion on the 26 points and Lickert scale of 1-5 rating was used to get the responses. Responses for 40 respondents (covering 6 Indian states) are analysed and the results are quite similar. 90% respondents agree that setting of new high tech labs and training for skill development, placement opportunities (Robotics, 3D Printing, Total Station QGIS, Revit, Sketch up), Functional MoUs with industries can help improve employability (with 70 % strongly agreeing). 90% respondents agree that finding out good sincere students (10-20%) i.e. segregation and grooming them in their field of interest, future plans can improve the knowledge, skill, attitude (KSA) for employment (with 50% strongly agreeing). 90% respondents agree that Self discipline /self management among students, attendance in college and responsibility in learning impact KSA of students (with 50% strongly agreeing). These responses are indicative that institutions need to align themselves in the changing times to make their students employable.
Biodiesels are substitute fuel sources that can be potential replacement to fossil fuels apart fr... more Biodiesels are substitute fuel sources that can be potential replacement to fossil fuels apart from being eco-friendly owing to their carbon-neutral nature. The energy originating from nature-based resources has a premium value due to its lowest environmental impact. The strategies that protect nature are grouped under a philosophy termed as ‘sustainability’. The biodiesel ought to give net energy acquire, have ecological advantages with financially serious, and producible in enormous amounts without diminishing food supplies. The proposed study examines potential of waste cooking oil as a source of bio-diesels by collecting samples of used cooking oil from the food outlets. The characteristics of producing bio-diesel from waste cooking oil are investigated from the point of view of utilizing it on a small batch mode of 5 to 10 litre. The chemistry of transesterification is investigated by adopting computational route to design a reactor and experimentally verifying the small-scale ...
Indian Railways has 45 workshops for maintenance of its fleet of rolling stock and out of them tw... more Indian Railways has 45 workshops for maintenance of its fleet of rolling stock and out of them two workshops catering to broad guage coach maintenance located in southern part of India have been studied for a period of five calendar years from 2007 till 2011 to analyse their output and the corresponding energy inputs. The various activities of the workshops viz. maintenance of coaches and other major works have been studied with respect to energy usage to arrive at a common unit of output for comparison. All the forms of energy input to these two workshops viz. Electricity supply from distribution companies, high speed diesel and LPG have been accounted for. The study finds that the energy requirement for undertaking the periodical overhauling activity per coach in both the workshops is showing a downward trend from a peak of 1110 kWh per coach during 2007 to less than 600 kWh as in 2011 which is gradual and consistent and correspondingly the total energy consumption and the power b...
Indian Railways (IR) has taken the lead and has planted Jatropha Curcas (Ratanjyot) saplings on a... more Indian Railways (IR) has taken the lead and has planted Jatropha Curcas (Ratanjyot) saplings on a massive scale on its vacant land as well as on either side of the tracks so that once these plants grow and start yielding fruits, the seeds can be used to extract oil which will be converted into Biodiesel (BD). This BD can be used as fuel in any diesel engine without much modification and as it is an environmentally friendly fuel its use is on the rise globally. For eg. France has made it mandatory to blend BD in Petroleum diesel (PD). US, Europe have taken lead and are manufacturing BD out of edible oils and using them extensively. BD is accepted as an alternate fuel by EPA of USA and India during the year 2005 has come out with an IS specification for BD (IS 15607:2005).
With the growing need of fuels for various activities like transportation and power generation th... more With the growing need of fuels for various activities like transportation and power generation the need for fuel has increased. Keeping this objective in mind we decided to pursue our project on production of biodiesel from algae. The reason we chose this as our project is because of ability to cultivate algae on large scale. After testing with other species of algae we chose Sargassum as it gave us 20-30% oil on 1 kg of algae. After the selection of the species we went to the Talpona beach in goa to search for the algae. We managed to collect 50kg of wet algae. After collecting the algae we dried the algae in the presence of sunlight. This was done to remove the water present in the algae. Once the drying processes was completed we moved to the grinding of the dried algae using a grinder. The powdered algae was boiled to obtain the oil. The oil that was obtained was used to generate biodiesel using the transesterification process in a biodiesel plant. We ran the biodiesel obtained ...
Energy conservation is the need of the hour in the world and more so in India, not only due to en... more Energy conservation is the need of the hour in the world and more so in India, not only due to energy imports and energy security concerns but also due to growing concerns of its environmental implications. Indian Railways (IR), the nations transport lifeline, is one of the nation’s major energy consumer and is passing through a difficult financial state due to high operating costs of which energy is one amongst them. Carriage Repair Workshops (CRWs) in IR undertake Periodical Overhauling (PoH) of coaches and are major consumers of energy in various forms, viz. petroleum diesel and electricity other than traction applications. CRWs were established in pre-independence era and over the years they have successfully implemented many state-of-the-art energy conservation measures (ECMs) using the latest technologies available globally. This study focuses on two CRWs both located in the south Indian state of Karnataka, one at north part of Karnataka, i.e. Hubli and the second one at Mysore which is in south Karnataka which are into PoH of coaches since several decades. The study delves into two aspects, viz. the drives which have promoted the ECM and the barriers which are impeding the implementation of ECM. Prioritization of barriers helps in focused attention and efforts in the process of overcoming them. The stakeholder’s perspective in any such prioritization scheme is essential and also rewarding. It is observed that the attrition rates in railways are very low and as such most of the employees have vast experience in the organization. To take advantage of the same, the main stakeholders (officers and engineers) of CRWs are interviewed and the various dimensions pertaining to drivers and barriers are collected by face-to-face interviews. Totally 124 respondents which comprise of one-third of the population including both the CRWs were involved in the study. Questionnaire was developed to rank the drivers and factor analysis approach was adopted to group the variables representing barriers into manageable factors and rank them. Forced ranking method was employed to rank the drivers and factor scores for prioritizing the barriers. Five-point Likert scale was used to measure the stakeholder’s perceptions regarding the 25 barrier dimensions in the factor analysis. The study revealed that topmost driver for ECM was “the drive by the workshop management” and the topmost barrier factor was “motivation of employees”. This underscores the need for policy reforms by IR for aggressive implementation of ECMs in CRWs for fruitful results in the years to come.
The paper describes fabrication of an E bike and its performance analysis by means of a dynamic m... more The paper describes fabrication of an E bike and its performance analysis by means of a dynamic model equipped with a suitable control for the management of the assisted drive of the e-bike. The main advantage of this approach consists of the opportunity to simulate different versions of performances, e-bikes characterized by different parameters (total mass, motor torque, top speeds under different load conditions) and different control strategies. The study also undertakes comparison of the e-bike with a regular e-bike. A test setup to see the difference between an e-bike with only assistance of a li-ion battery package and the second with the assistance of a li-ion battery pack along with supercapacitors. The basic approach to this study is to confirm the fact that the li-ion battery performance and range can be improved with the combination of super capacitors.
This paper undertakes study of two railway coach repair workshops located in South India involved... more This paper undertakes study of two railway coach repair workshops located in South India involved in periodical overhauling of broad gauge passenger coaches. The study takes into account the various activities in terms of maintenance of coaches and production of components the energy input for Carriage Repair Workshop Hubli (UBLS) and Central workshop, Mysore (MYSS). The specific energy consumption of larger workshop i.e. UBLS is comparatively less than the smaller one i.e. MYSS due to introduction and successful maintenance of many a energy conservation measures. Hence extended study was undertaken to analyse the drivers for energy efficiency and 82 respondents out of 235 supervisors were interviewed separately and their opinion on the rating of drivers for energy conservation (EC) were sought. The entire workshop supervisors were divided into four groups based on their functions viz. Electrical supervisors, Carriage Maintenance Supervisors, Production shop supervisors and lastly t...
The Loco, Carriage and Wagon Workshop at Hubli was established in 1885 under Southern Mahratta Ra... more The Loco, Carriage and Wagon Workshop at Hubli was established in 1885 under Southern Mahratta Railway (SMR) headquartered at Dharwar for maintenance of meter gauge locomotives, coaches and wagons. In 1919 Madras & Southern Mahratta Railway (MSMR) was formed and the workshop was brought under the jurisdiction of MSMR. The workshop continued with periodic overhauling activities of metre gauge rolling stock.
In order to facilitate use of vegetable oils as alternate fuels for CI engines their viscosity ne... more In order to facilitate use of vegetable oils as alternate fuels for CI engines their viscosity needs to be considerably reduced which can be carried out by various means. One of the most popular means of reducing the viscosity of the vegetable oils is by means of transesterification using an alcohol and a catalyst. In this work, efforts were carried out to successfully transesterify two non edible vegetable oils viz. Jatropha curcas oil and Pongemia Pinnata (Honge) oils by using Methyl alcohol and Potassium Hydroxide as the catalyst. The easiest procedure to manufacture biodiesel (base catalysed process) is described which includes determining of free fatty acid content of the oils. Presently various education and research institutions are carrying out the transesterification using trial and error methods which lead to wastage of oil, alcohol and requires considerable amount of time. By carrying out experiments using various combinations the correct procedure for transesterifying the vegetable oils giving the highest yield has been derived which is described in this paper. Even used cooking oils from houses, restaurants etc. can be used to manufacture biodiesel successfully.
Journal of Materials Research and Technology, 2020
Abstract Herein, we report a study on the performance of two well-known benzo [1,2-b:4,5-b']d... more Abstract Herein, we report a study on the performance of two well-known benzo [1,2-b:4,5-b']dithiophene (BDT) based donor-acceptor (D-A) copolymers for organic photodiode (OPD) application. Judicious material design motif via side-chain and acceptor unit alteration in both polymers resulted in the donor moieties namely, PBDTS-TDZ and PBDB-T, which were applied as active layers with fullerene derivative PC61BM in a bulk heterojunction OPD. Panchromatic light detection was afforded despite the molecular and structural changes in both polymers. Inverted OPD based on PBDB-T: PC61BM showed a comparatively broader photoresponse and better performance, with specific detectivity [EQE] of 3.749 × 1012 [62%] at a bias voltage of 2 V under red light illumination. This work entrenches the inter-dependent relationship existing between polymer structural design and their device performance for organic photodiode (OPD) application.
Abstract The energy storage prospects of organic molecule has recently rendered them as promising... more Abstract The energy storage prospects of organic molecule has recently rendered them as promising candidates for supercapacitors (SCs) applications. Herein, we report an investigation into the electrochemical and energy storage capability of two carbazole based monomer and dimer moieties, connected through mono (CBZ-1) and diacetylene (CBZ-2)-based linkages. Synthesized intermediates and final compounds were experimentally and theoretically characterized via spectral, scanning electron microscopy (SEM) analysis and density functional theory (DFT) calculations respectively. Excellent electrochemical properties were observed in an organic pseudo-capacitive-supercapacitor (SC) based on the carbazole derivatives, with the dimer (CBZ-2) functionalized with diacetylene showing a comparatively better capacitive and improved electrochemical characteristics (398 F.g-1 at a current density of 1 A.g-1) than the mono (CBZ-1) derivative.
Abstract The high trap-state density and low conductivity in compact TiO2 (c-TiO2) layer limits t... more Abstract The high trap-state density and low conductivity in compact TiO2 (c-TiO2) layer limits the power conversion efficiency (PCE) of organic-inorganic hybrid perovskite solar cells (HPSCs). Metal doping in c-TiO2 has been proven to be a successful strategy for enhancing the PCE of HPSCs. Herein, Zr is incorporated in the c-TiO2 layer with different doping concentrations, and its impact on the photovoltaic performance of methylammonium lead iodide (MAPbI3) HPSCs is investigated. Inclusion of Zr enhances the charge carrier collection at TiO2/perovskite junction as well as conductivity of TiO2 layer. It is demonstrated that Zr-doping reduces the dark current significantly by suppressing non-geminated recombinations, leakage path, and electron trap-states. As a result, the HPSCs with optimum Zr-doping (10 vol%) exhibits open-circuit voltage (VOC) of 1.076 V, short-circuit current density (JSC) of 23.57 mA cm−2, and PCE of 18.16% under one-sun illumination conditions. UV absorption confirms the increase in bandgap upon Zr-doping that leads to favorable band alignment with the perovskite layer. Further, the engineered solar cells are probed for current density-voltage (J-V) hysteresis, operational stability, leakage current, intensity-dependence behavior, and electrochemical impedance spectroscopy (EIS).
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Papers by Suresh D Mane