Novel Combination of Efficient Perovskite Solar Cells with Low Temperature Processed Compact TiO₂ Layer via Anodic Oxidation

In this work, a facile and low temperature processed anodic oxidation approach is proposed for fabricating compact and homogeneous titanium dioxide film (AO-TiO₂). In order to realize morphology and thickness control of AO-TiO₂, the theory concerning anodic oxidation (AO) is unveiled and the influence of relevant parameters during the process of AO such as electrolyte ingredient and oxidation voltage on AO-TiO₂ formation is observed as well. Meanwhile, we demonstrate that the planar perovskite solar cells (p-PSCs) fabricated in ambient air and utilizing optimized AO-TiO₂ as electron transport layer (ETL) can deliver repeatable power conversion efficiency (PCE) over 13%, which possess superior open-circuit voltage (Voc) and higher fill factor (FF) compared to its counterpart utilizing conventional high temperature processed compact TiO₂ (c-TiO₂) as ETL. Through a further comparative study, it is indicated that the improvement of device performance should be attributed to more effective electron collection from perovskite layer to AO-TiO₂ and the decrease of device series resistance. Furthermore, hysteresis effect about current density–voltage (<i>J</i>–<i>V</i>) curves in TiO₂-based p-PSCs is also unveiled

New Films on Old Substrates: Toward Green and Sustainable Energy Production via Recycling of Functional Components from Degraded Perovskite Solar Cells

The development of solution processable perovskite solar cells (PSCs) has progressed rapidly, and the their highest power conversion efficiency (PCE) has recently surpassed 22%. Further studies to promote market-oriented PSCs call for further reducing the manufacturing cost of the device and addressing the concerns about the possible outflow of toxic lead. To reduce the level of environmental pollution and prevent the health hazard caused by degraded devices (solid waste) and possible lead outflow and to conserve resources, we adopted low-temperature solution-processed, multirecycled glass/FTO/c-TiO₂ (m-TiO₂) substrates from the degraded devices to fabricate efficient planar heterojunction (PH) and mesoporous (M) PSCs in an environmentally friendly and energy-conserving manner. This is realized by simple and low-temperature processes, including organic solvent washing, ultrasonic cleaning, and UV–ozone treatment. After two rounds of substrate recycling, the PH PSC and M PSC still exhibited peak efficiencies of 11.87% and 11.03%, respectively, indicating the feasibility of recycling used substrates for sustainable, energy and resource conservation-oriented, and environmentally friendly energy production

New Films on Old Substrates: Toward Green and Sustainable Energy Production via Recycling of Functional Components from Degraded Perovskite Solar Cells

The development of solution processable perovskite solar cells (PSCs) has progressed rapidly, and the their highest power conversion efficiency (PCE) has recently surpassed 22%. Further studies to promote market-oriented PSCs call for further reducing the manufacturing cost of the device and addressing the concerns about the possible outflow of toxic lead. To reduce the level of environmental pollution and prevent the health hazard caused by degraded devices (solid waste) and possible lead outflow and to conserve resources, we adopted low-temperature solution-processed, multirecycled glass/FTO/c-TiO₂ (m-TiO₂) substrates from the degraded devices to fabricate efficient planar heterojunction (PH) and mesoporous (M) PSCs in an environmentally friendly and energy-conserving manner. This is realized by simple and low-temperature processes, including organic solvent washing, ultrasonic cleaning, and UV–ozone treatment. After two rounds of substrate recycling, the PH PSC and M PSC still exhibited peak efficiencies of 11.87% and 11.03%, respectively, indicating the feasibility of recycling used substrates for sustainable, energy and resource conservation-oriented, and environmentally friendly energy production

New Films on Old Substrates: Toward Green and Sustainable Energy Production via Recycling of Functional Components from Degraded Perovskite Solar Cells

The development of solution processable perovskite solar cells (PSCs) has progressed rapidly, and the their highest power conversion efficiency (PCE) has recently surpassed 22%. Further studies to promote market-oriented PSCs call for further reducing the manufacturing cost of the device and addressing the concerns about the possible outflow of toxic lead. To reduce the level of environmental pollution and prevent the health hazard caused by degraded devices (solid waste) and possible lead outflow and to conserve resources, we adopted low-temperature solution-processed, multirecycled glass/FTO/c-TiO₂ (m-TiO₂) substrates from the degraded devices to fabricate efficient planar heterojunction (PH) and mesoporous (M) PSCs in an environmentally friendly and energy-conserving manner. This is realized by simple and low-temperature processes, including organic solvent washing, ultrasonic cleaning, and UV–ozone treatment. After two rounds of substrate recycling, the PH PSC and M PSC still exhibited peak efficiencies of 11.87% and 11.03%, respectively, indicating the feasibility of recycling used substrates for sustainable, energy and resource conservation-oriented, and environmentally friendly energy production

New Films on Old Substrates: Toward Green and Sustainable Energy Production via Recycling of Functional Components from Degraded Perovskite Solar Cells

The development of solution processable perovskite solar cells (PSCs) has progressed rapidly, and the their highest power conversion efficiency (PCE) has recently surpassed 22%. Further studies to promote market-oriented PSCs call for further reducing the manufacturing cost of the device and addressing the concerns about the possible outflow of toxic lead. To reduce the level of environmental pollution and prevent the health hazard caused by degraded devices (solid waste) and possible lead outflow and to conserve resources, we adopted low-temperature solution-processed, multirecycled glass/FTO/c-TiO₂ (m-TiO₂) substrates from the degraded devices to fabricate efficient planar heterojunction (PH) and mesoporous (M) PSCs in an environmentally friendly and energy-conserving manner. This is realized by simple and low-temperature processes, including organic solvent washing, ultrasonic cleaning, and UV–ozone treatment. After two rounds of substrate recycling, the PH PSC and M PSC still exhibited peak efficiencies of 11.87% and 11.03%, respectively, indicating the feasibility of recycling used substrates for sustainable, energy and resource conservation-oriented, and environmentally friendly energy production

Flexible Perovskite Solar Cells onto Plastic Substrate Exceeding 13% Efficiency Owing to the Optimization of CH₃NH₃PbI_3–<i>x</i>Cl_<i>x</i> Film via H₂O Additive

In this work, flexible perovskite solar cells (F-PSCs) are fabricated utilizing the device polyethylene terephthalate (PET) substrate/ITO/PEDOT:PSS/CH₃NH₃PbI_3–<i>x</i>Cl_<i>x</i>/PCBM/Ag, which exhibits the optimal power conversion efficiency (PCE) reaching 13.27%, superb stability against bending deformation, and advantageous stability in ambient atmosphere without encapsulation. Meanwhile, we herein confirm a fact that incorporating suitable H₂O additive into the perovskite precursor solution leads to an enhanced CH₃NH₃PbI_3–<i>x</i>Cl_<i>x</i> perovskite quality for F-PSCs application, including the improvement of morphology and electrical properties. To better summarize the mechanism concerning how H₂O additive affects the perovskite film quality, CH₃NH₃PbI_3–<i>x</i>Cl_<i>x</i> films are prepared by a simple one-step spinning method from a solution containing CH₃NH₃I, PbI₂, and PbCl₂ in a mixed solvent of H₂O and dimethylformamide (DMF) with solely various volume ratio ranging from 0.1% to 0.9%. Through a comparative analysis, it is proposed that H₂O additive prolongs the CH₃NH₃PbI_3–<i>x</i>Cl_<i>x</i> recrystallization process contributing to slower crystallization rate. Additionally, it can merge adjacent perovskite grain together by accelerating the diffusion of ions within the predeposited films toward the grain boundary, thereby yielding large and densely packed perovskite grain size

UV-Sintered Low-Temperature Solution-Processed SnO₂ as Robust Electron Transport Layer for Efficient Planar Heterojunction Perovskite Solar Cells

Recently, low temperature solution-processed tin oxide (SnO₂) as a versatile electron transport layer (ETL) for efficient and robust planar heterojunction (PH) perovskite solar cells (PSCs) has attracted particular attention due to its outstanding properties such as high optical transparency, high electron mobility, and suitable band alignment. However, for most of the reported works, an annealing temperature of 180 °C is generally required. This temperature is reluctantly considered to be a low temperature, especially with respect to the flexible application where 180 °C is still too high for the polyethylene terephthalate flexible substrate to bear. In this contribution, low temperature (about 70 °C) UV/ozone treatment was applied to in situ synthesis of SnO₂ films deposited on the fluorine-doped tin oxide substrate as ETL. This method is a facile photochemical treatment which is simple to operate and can easily eliminate the organic components. Accordingly, PH PSCs with UV-sintered SnO₂ films as ETL were successfully fabricated for the first time. The device exhibited excellent photovoltaic performance as high as 16.21%, which is even higher than the value (11.49%) reported for a counterpart device with solution-processed and high temperature annealed SnO₂ films as ETL. These low temperature solution-processed and UV-sintered SnO₂ films are suitable for the low-cost, large yield solution process on a flexible substrate for optoelectronic devices