With the accelerated development of new lead-free metal halide perovskites, whose chemical and ph... more With the accelerated development of new lead-free metal halide perovskites, whose chemical and physical properties are very different from their so-studied classical Pb-containing counterparts, finding suitable synthetic methodologies for these...
The in‐situ deposition of emerging organic–inorganic metal halides (OIMHs) films on glass or stre... more The in‐situ deposition of emerging organic–inorganic metal halides (OIMHs) films on glass or stretchable substrates has been challenging, and no methodology has been reported to achieve this goal. The aerosol‐assisted chemical vapor deposition technique using an antisolvent‐enhanced crystallization process (AEC‐AACVD) is a simple, cost‐effective, scalable, and high‐throughput technique operated under ambient atmosphere and pressure. The AEC‐AACVD technique (an all‐green chemistry methodology) was used in this work to deposit TPA2MnCl2Br2 luminescent films on glass and highly stretchable elastomer substrates. The effect of using different antisolvents on the structural, morphological, and photoluminescent characteristics of films deposited on glass is reported. It was found that the intensity of the characteristic green emission peaked at 511 nm for this OIMH, improving with the antisolvent application. The TPA2MnCl2Br2 films deposited using a mixture of antisolvents resulted in the ...
A huge family of luminescent low-dimensional metal halides for optoelectronic applications has em... more A huge family of luminescent low-dimensional metal halides for optoelectronic applications has emerged recently as a green alternative to the highly toxic lead halide phosphors. To date, studies on the controlled deposition of these materials as films to be integrated into optoelectronic architectures remain scarce. Here, the synthesis and characterization of highly luminescent films of copper halide phosphors with emissions in violet: K2CuCl3, blue: Cs5Cu3Cl6I2, and green: Cs3Cu2Cl5 are reported. The films were obtained by multisource aerosol-assisted chemical vapor deposition (AACVD) from methanolic solutions at low temperature and under ambient conditions. Photoluminescent quantum yield values obtained for the films deposited on quartz substrates have values of 52% for K2CuCl3, 85% for Cs5Cu3Cl6I2, and 99% for Cs3Cu2Cl5. These values were highly influenced by the substrate since for samples deposited on glass substrates the values are 26.17% for K2CuCl3, 60.47% for Cs5Cu3Cl6I2, a...
Adding isopropylamonium cation in quasi-2D perovskite films leads to a change in phase distributi... more Adding isopropylamonium cation in quasi-2D perovskite films leads to a change in phase distribution and orientation of crystalline domains, with efficient sky blue emission. This allows the fabrication of LEDs with high luminescence and color purity.
Abstract In this work, white-emitting-alternating-current-thin film electroluminescent (w-ACTFEL)... more Abstract In this work, white-emitting-alternating-current-thin film electroluminescent (w-ACTFEL) devices are demonstrated using europium-doped zinc sulfide (ZnS:Eu) and zirconium oxide (ZrO2) as the emissive and dielectric layers, respectively. These films were deposited by the ultrasonic spray pyrolysis technique on antimony-doped tin oxide glass substrates, forming a standard metal-insulator-semiconductor-insulator-metal (MISIM) architecture. 10 kHz sinusoidal voltages activated the white-EL of the devices. The colorimetric characteristics were investigated for three amplitudes of the applied voltage. The emission of the devices is made up of wide and narrow bands with peaks corresponding to violet, blue, green and red light, which together produce the resulting white light. According to the colorimetric analysis, this white light is close to the standard D65 CIE illuminant with a minimal dominant blue component. The variation in voltage amplitude induces small changes in the visual characteristics of the EL emission. The white-EL emission of these MISIM devices is attributed to the electron-impact excitation and subsequent relaxation of the excited levels of Eu2+ and Eu3+ impurities, and defect levels in the sublayer regions adjacent to the ZrO2–ZnS:Eu interfaces.
The fabrication of NiO films by different routes is important to extend and improve their applica... more The fabrication of NiO films by different routes is important to extend and improve their applications as hole-transporting layers in organic and inorganic optoelectronic devices. Here, an automated ultrasonic pyrolysis spray method was used to fabricate NiO and Li-doped NiO thin films using nickel acetylacetonate and lithium acetate dihydrate as metal precursor and dimethylformamide as solvent. The effect of the amount of lithium in the precursor solution on the structural, morphological, optical, and electrical properties were studied. XRD results reveal that all the samples are polycrystalline with cubic structure and crystallite sizes in the range of 21 to 25 nm, without any clear trend with the Li doping level. AFM analysis shows that the crystallites form round-shaped aggregates and all the films have low roughness. The optical transmittance of the films reaches values of 60% to 77% with tendency upward as Li content is increased. The electrical study shows that the films are ...
Nowadays, the use of plasmonic metal layers to improve the photonic emission characteristics of s... more Nowadays, the use of plasmonic metal layers to improve the photonic emission characteristics of several semiconductor quantum dots is a booming tool. In this work, we report the use of silicon quantum dots (SiQDs) embedded in a silicon nitride thin film coupled with an ultra-thin gold film (AuNPs) to fabricate light emitting devices. We used the remote plasma enhanced chemical vapor deposition technique (RPECVD) in order to grow two types of silicon nitride thin films. One with an almost stoichiometric composition, acting as non-radiative spacer; the other one, with a silicon excess in its chemical composition, which causes the formation of silicon quantum dots imbibed in the silicon nitride thin film. The ultra-thin gold film was deposited by the direct current (DC)-sputtering technique, and an aluminum doped zinc oxide thin film (AZO) which was deposited by means of ultrasonic spray pyrolysis, plays the role of the ohmic metal-like electrode. We found that there is a maximum elect...
In this work, white-emitting-alternating-current-thin film electroluminescent (w-ACTFEL) devices ... more In this work, white-emitting-alternating-current-thin film electroluminescent (w-ACTFEL) devices are demonstrated using europium-doped zinc sulfide (ZnS:Eu) and zirconium oxide (ZrO2) as the emissive and dielectric layers, respectively. These films were deposited by the ultrasonic spray pyrolysis technique on antimony-doped tin oxide glass substrates, forming a standard metal-insulator-semiconductor-insulator-metal (MISIM) architecture. 10 kHz sinusoidal voltages activated the white-EL of the devices. The colorimetric characteristics were investigated for three amplitudes of the applied voltage. The emission of the devices is made up of wide and narrow bands with peaks corresponding to violet, blue, green and red light, which together produce the resulting white light. According to the colorimetric analysis, this white light is close to the standard D65 CIE illuminant with a minimal dominant blue component. The variation in voltage amplitude induces small changes in the visual chara...
Eu2+-Doped ZnS (ZnS:Eu2+) thin (∼550 nm) films with strong and stable blue photoluminescence have... more Eu2+-Doped ZnS (ZnS:Eu2+) thin (∼550 nm) films with strong and stable blue photoluminescence have been successfully synthesized by a simple and fast ultrasonic spray pyrolysis method.
The photoluminescence (PL) evolution of SiQDs respect deposition and annealing temperatures is st... more The photoluminescence (PL) evolution of SiQDs respect deposition and annealing temperatures is studied in a combined manner. The PL identified changes are associated to changes in thin film composition. 150 °C is identified as an important threshold.
The photoluminescence (PL) evolution of SiQDs respect deposition and annealing temperatures is st... more The photoluminescence (PL) evolution of SiQDs respect deposition and annealing temperatures is studied in a combined manner. The PL identified changes are associated to changes in thin film composition. 150 °C is identified as an important threshold.
With the accelerated development of new lead-free metal halide perovskites, whose chemical and ph... more With the accelerated development of new lead-free metal halide perovskites, whose chemical and physical properties are very different from their so-studied classical Pb-containing counterparts, finding suitable synthetic methodologies for these...
The in‐situ deposition of emerging organic–inorganic metal halides (OIMHs) films on glass or stre... more The in‐situ deposition of emerging organic–inorganic metal halides (OIMHs) films on glass or stretchable substrates has been challenging, and no methodology has been reported to achieve this goal. The aerosol‐assisted chemical vapor deposition technique using an antisolvent‐enhanced crystallization process (AEC‐AACVD) is a simple, cost‐effective, scalable, and high‐throughput technique operated under ambient atmosphere and pressure. The AEC‐AACVD technique (an all‐green chemistry methodology) was used in this work to deposit TPA2MnCl2Br2 luminescent films on glass and highly stretchable elastomer substrates. The effect of using different antisolvents on the structural, morphological, and photoluminescent characteristics of films deposited on glass is reported. It was found that the intensity of the characteristic green emission peaked at 511 nm for this OIMH, improving with the antisolvent application. The TPA2MnCl2Br2 films deposited using a mixture of antisolvents resulted in the ...
A huge family of luminescent low-dimensional metal halides for optoelectronic applications has em... more A huge family of luminescent low-dimensional metal halides for optoelectronic applications has emerged recently as a green alternative to the highly toxic lead halide phosphors. To date, studies on the controlled deposition of these materials as films to be integrated into optoelectronic architectures remain scarce. Here, the synthesis and characterization of highly luminescent films of copper halide phosphors with emissions in violet: K2CuCl3, blue: Cs5Cu3Cl6I2, and green: Cs3Cu2Cl5 are reported. The films were obtained by multisource aerosol-assisted chemical vapor deposition (AACVD) from methanolic solutions at low temperature and under ambient conditions. Photoluminescent quantum yield values obtained for the films deposited on quartz substrates have values of 52% for K2CuCl3, 85% for Cs5Cu3Cl6I2, and 99% for Cs3Cu2Cl5. These values were highly influenced by the substrate since for samples deposited on glass substrates the values are 26.17% for K2CuCl3, 60.47% for Cs5Cu3Cl6I2, a...
Adding isopropylamonium cation in quasi-2D perovskite films leads to a change in phase distributi... more Adding isopropylamonium cation in quasi-2D perovskite films leads to a change in phase distribution and orientation of crystalline domains, with efficient sky blue emission. This allows the fabrication of LEDs with high luminescence and color purity.
Abstract In this work, white-emitting-alternating-current-thin film electroluminescent (w-ACTFEL)... more Abstract In this work, white-emitting-alternating-current-thin film electroluminescent (w-ACTFEL) devices are demonstrated using europium-doped zinc sulfide (ZnS:Eu) and zirconium oxide (ZrO2) as the emissive and dielectric layers, respectively. These films were deposited by the ultrasonic spray pyrolysis technique on antimony-doped tin oxide glass substrates, forming a standard metal-insulator-semiconductor-insulator-metal (MISIM) architecture. 10 kHz sinusoidal voltages activated the white-EL of the devices. The colorimetric characteristics were investigated for three amplitudes of the applied voltage. The emission of the devices is made up of wide and narrow bands with peaks corresponding to violet, blue, green and red light, which together produce the resulting white light. According to the colorimetric analysis, this white light is close to the standard D65 CIE illuminant with a minimal dominant blue component. The variation in voltage amplitude induces small changes in the visual characteristics of the EL emission. The white-EL emission of these MISIM devices is attributed to the electron-impact excitation and subsequent relaxation of the excited levels of Eu2+ and Eu3+ impurities, and defect levels in the sublayer regions adjacent to the ZrO2–ZnS:Eu interfaces.
The fabrication of NiO films by different routes is important to extend and improve their applica... more The fabrication of NiO films by different routes is important to extend and improve their applications as hole-transporting layers in organic and inorganic optoelectronic devices. Here, an automated ultrasonic pyrolysis spray method was used to fabricate NiO and Li-doped NiO thin films using nickel acetylacetonate and lithium acetate dihydrate as metal precursor and dimethylformamide as solvent. The effect of the amount of lithium in the precursor solution on the structural, morphological, optical, and electrical properties were studied. XRD results reveal that all the samples are polycrystalline with cubic structure and crystallite sizes in the range of 21 to 25 nm, without any clear trend with the Li doping level. AFM analysis shows that the crystallites form round-shaped aggregates and all the films have low roughness. The optical transmittance of the films reaches values of 60% to 77% with tendency upward as Li content is increased. The electrical study shows that the films are ...
Nowadays, the use of plasmonic metal layers to improve the photonic emission characteristics of s... more Nowadays, the use of plasmonic metal layers to improve the photonic emission characteristics of several semiconductor quantum dots is a booming tool. In this work, we report the use of silicon quantum dots (SiQDs) embedded in a silicon nitride thin film coupled with an ultra-thin gold film (AuNPs) to fabricate light emitting devices. We used the remote plasma enhanced chemical vapor deposition technique (RPECVD) in order to grow two types of silicon nitride thin films. One with an almost stoichiometric composition, acting as non-radiative spacer; the other one, with a silicon excess in its chemical composition, which causes the formation of silicon quantum dots imbibed in the silicon nitride thin film. The ultra-thin gold film was deposited by the direct current (DC)-sputtering technique, and an aluminum doped zinc oxide thin film (AZO) which was deposited by means of ultrasonic spray pyrolysis, plays the role of the ohmic metal-like electrode. We found that there is a maximum elect...
In this work, white-emitting-alternating-current-thin film electroluminescent (w-ACTFEL) devices ... more In this work, white-emitting-alternating-current-thin film electroluminescent (w-ACTFEL) devices are demonstrated using europium-doped zinc sulfide (ZnS:Eu) and zirconium oxide (ZrO2) as the emissive and dielectric layers, respectively. These films were deposited by the ultrasonic spray pyrolysis technique on antimony-doped tin oxide glass substrates, forming a standard metal-insulator-semiconductor-insulator-metal (MISIM) architecture. 10 kHz sinusoidal voltages activated the white-EL of the devices. The colorimetric characteristics were investigated for three amplitudes of the applied voltage. The emission of the devices is made up of wide and narrow bands with peaks corresponding to violet, blue, green and red light, which together produce the resulting white light. According to the colorimetric analysis, this white light is close to the standard D65 CIE illuminant with a minimal dominant blue component. The variation in voltage amplitude induces small changes in the visual chara...
Eu2+-Doped ZnS (ZnS:Eu2+) thin (∼550 nm) films with strong and stable blue photoluminescence have... more Eu2+-Doped ZnS (ZnS:Eu2+) thin (∼550 nm) films with strong and stable blue photoluminescence have been successfully synthesized by a simple and fast ultrasonic spray pyrolysis method.
The photoluminescence (PL) evolution of SiQDs respect deposition and annealing temperatures is st... more The photoluminescence (PL) evolution of SiQDs respect deposition and annealing temperatures is studied in a combined manner. The PL identified changes are associated to changes in thin film composition. 150 °C is identified as an important threshold.
The photoluminescence (PL) evolution of SiQDs respect deposition and annealing temperatures is st... more The photoluminescence (PL) evolution of SiQDs respect deposition and annealing temperatures is studied in a combined manner. The PL identified changes are associated to changes in thin film composition. 150 °C is identified as an important threshold.
In this work a comprehensive model for the optical transmission as a function of wavelength and t... more In this work a comprehensive model for the optical transmission as a function of wavelength and thickness of ZnO :Al films deposited on glass substrates by ultrasonic spray pyrolysis, is developed. The mathematical expression developed for the transmission of the transparent conducting film on a transparent substrate, considers: 1) the interference effects of multiple specular reflections of coherent light from the front and the back of the flat-parallel-sided interfaces film-air and filmglass substrate, 2) the contribution of free carrier concentration (electrons in the conduction band due to Al doping) to the weak absorption in the visible and nearinfrared range, 3) the Urbach tail absorption edge at the low wavelength region (< 400 nm), 4) the effect of surface diffuse scattering of light originated by the roughness of these interfaces on the specular reflection and transmission coefficients. The wavelength dependence of the coefficients of reflection and transmission, and the absorption coefficient of the ZnO :Al film in the low absorptionvisible region (400-800 nm), were calculated from the formulas derived for the refractive index and extinction coefficient by using a LorentzDrude expression to separate the contribution of the bound-electrons and free-electrons, respectively, to the complex dielectric function. The carrier concentration and dc-electrical
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Papers by Juan Carlos Alonso Huitrón