Conventional flexible mono-crystalline silicon (Si) solar cells have a front-side contact. In thi... more Conventional flexible mono-crystalline silicon (Si) solar cells have a front-side contact. In this work we show innovative inter-digitated back contact for flexible mono-crystalline silicon solar cell. We also report the efficiency for different released thickness using a novel flex-Si process, which controls the thickness to reduce the required diffusion path for the generated minority carriers to reach the P-N junction. Additionally, nickel silicidation has been formed before the metal contact deposition. The fabrication starts with a P-type Si < 100 > wafer (1-30 Ω-cm, 500 μ m thickness). First step was depositing SiO2 (950 nm) on the whole wafer using Plasma Enhanced Chemical Vapor Deposition (PECVD). Respectively, n+ areas were defined through lithography pattering after etching the SiO2 in Reactive Ion Etching (RIE). Source diffusion (Phosphorous TP-250) was used to create N+/P lateral junction. After the N+/P lateral junction formed, lithography patterning was used to l...
In this era of strong and global push for sustainable future, researchers and technologists are f... more In this era of strong and global push for sustainable future, researchers and technologists are focusing on enhancing clean and renewable energy solutions. However, there are still many concerns need to be addressed before renewable energy technologies become viable to be integrated into mainstream energy market. We report a novel flexible solar cell design incorporating key features: high efficiency, low cost, lightweight, flexible, and mono-crystalline silicon solar cell. Our fabrication process is CMOS compatible, uses bulk mono-crystalline Si (100) – the most widely used substrate for its low coat and exclusive electrical and mechanical properties. The resultant thin photoactive layers have high flexibility, periodic arrays of nano-structured junctions that dramatically amplify absorption while decreasing system parasitic resistance. We recycle the remaining bulk wafers (after releasing the top thin layer) by chemical mechanical polishing to reduce the cost further
Micro- and Nanotechnology Sensors, Systems, and Applications VI, 2014
ABSTRACT With the emergence of cloud computation, we are facing the rising waves of big data. It ... more ABSTRACT With the emergence of cloud computation, we are facing the rising waves of big data. It is our time to leverage such opportunity by increasing data usage both by man and machine. We need ultra-mobile computation with high data processing speed, ultra-large memory, energy efficiency and multi-functionality. Additionally, we have to deploy energy-efficient multi-functional 3D ICs for robust cyber-physical system establishment. To achieve such lofty goals we have to mimic human brain, which is inarguably the world’s most powerful and energy efficient computer. Brain’s cortex has folded architecture to increase surface area in an ultra-compact space to contain its neuron and synapses. Therefore, it is imperative to overcome two integration challenges: (i) finding out a low-cost 3D IC fabrication process and (ii) foldable substrates creation with ultra-large-scale-integration of high performance energy efficient electronics. Hence, we show a low-cost generic batch process based on trench-protect-peel-recycle to fabricate rigid and flexible 3D ICs as well as high performance flexible electronics. As of today we have made every single component to make a fully flexible computer including non-planar state-of-the-art FinFETs. Additionally we have demonstrated various solid-state memory, movable MEMS devices, energy harvesting and storage components. To show the versatility of our process, we have extended our process towards other inorganic semiconductor substrates such as silicon germanium and III-V materials. Finally, we report first ever fully flexible programmable silicon based microprocessor towards foldable brain computation and wirelessly programmable stretchable and flexible thermal patch for pain management for smart bionics.
Conventional flexible mono-crystalline silicon (Si) solar cells have a front-side contact. In thi... more Conventional flexible mono-crystalline silicon (Si) solar cells have a front-side contact. In this work we show innovative inter-digitated back contact for flexible mono-crystalline silicon solar cell. We also report the efficiency for different released thickness using a novel flex-Si process, which controls the thickness to reduce the required diffusion path for the generated minority carriers to reach the P-N junction. Additionally, nickel silicidation has been formed before the metal contact deposition. The fabrication starts with a P-type Si < 100 > wafer (1-30 Ω-cm, 500 μ m thickness). First step was depositing SiO2 (950 nm) on the whole wafer using Plasma Enhanced Chemical Vapor Deposition (PECVD). Respectively, n+ areas were defined through lithography pattering after etching the SiO2 in Reactive Ion Etching (RIE). Source diffusion (Phosphorous TP-250) was used to create N+/P lateral junction. After the N+/P lateral junction formed, lithography patterning was used to l...
In this era of strong and global push for sustainable future, researchers and technologists are f... more In this era of strong and global push for sustainable future, researchers and technologists are focusing on enhancing clean and renewable energy solutions. However, there are still many concerns need to be addressed before renewable energy technologies become viable to be integrated into mainstream energy market. We report a novel flexible solar cell design incorporating key features: high efficiency, low cost, lightweight, flexible, and mono-crystalline silicon solar cell. Our fabrication process is CMOS compatible, uses bulk mono-crystalline Si (100) – the most widely used substrate for its low coat and exclusive electrical and mechanical properties. The resultant thin photoactive layers have high flexibility, periodic arrays of nano-structured junctions that dramatically amplify absorption while decreasing system parasitic resistance. We recycle the remaining bulk wafers (after releasing the top thin layer) by chemical mechanical polishing to reduce the cost further
Micro- and Nanotechnology Sensors, Systems, and Applications VI, 2014
ABSTRACT With the emergence of cloud computation, we are facing the rising waves of big data. It ... more ABSTRACT With the emergence of cloud computation, we are facing the rising waves of big data. It is our time to leverage such opportunity by increasing data usage both by man and machine. We need ultra-mobile computation with high data processing speed, ultra-large memory, energy efficiency and multi-functionality. Additionally, we have to deploy energy-efficient multi-functional 3D ICs for robust cyber-physical system establishment. To achieve such lofty goals we have to mimic human brain, which is inarguably the world’s most powerful and energy efficient computer. Brain’s cortex has folded architecture to increase surface area in an ultra-compact space to contain its neuron and synapses. Therefore, it is imperative to overcome two integration challenges: (i) finding out a low-cost 3D IC fabrication process and (ii) foldable substrates creation with ultra-large-scale-integration of high performance energy efficient electronics. Hence, we show a low-cost generic batch process based on trench-protect-peel-recycle to fabricate rigid and flexible 3D ICs as well as high performance flexible electronics. As of today we have made every single component to make a fully flexible computer including non-planar state-of-the-art FinFETs. Additionally we have demonstrated various solid-state memory, movable MEMS devices, energy harvesting and storage components. To show the versatility of our process, we have extended our process towards other inorganic semiconductor substrates such as silicon germanium and III-V materials. Finally, we report first ever fully flexible programmable silicon based microprocessor towards foldable brain computation and wirelessly programmable stretchable and flexible thermal patch for pain management for smart bionics.
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Papers by Rabab Bahabry