ZnO Buffer Layers and Nanowires Electrodeposition for Extremely Thin Absorber Solar Cells

Abstract Solar energy is found to be low cost and abundant of all available energy resources and needs exploration of highly efficient devices for global energy requirements. We have investigated methyl ammonium tin halide (CH3NH3SnI3)-based perovskite solar cells (PSCs) for optimized device performance using solar capacitance simulator SCAPS-1D software. This study is a step forward towards availability of stable and non-toxic solar cells. We explored all necessary parameters such as metal work functions, thickness of absorber and buffer layers, charge carrier’s mobility and defect density for improved device performance. Calculations revealed that for the best efficiency of device the maximum thickness of the perovskite absorber layer must be 4.2 μm. Furthermore, optimized thickness values of (ZnO=0.01 μm) as electron transport layer (ETL), GaAs as hole transport layer (HTL=3.02 μm) and (CdS=10 nm) and buffer layer have provided power conversion efficiency (PCE) of 23.53%. Variation of open circuit voltage (Voc), Short circuit current (Jsc), Fill Factor (FF%) and quantum efficiency against thickness of all layers in FTO/ZnO/CdS/CH3NH3SnI3/GaAs/Au compositions have been critically explored and reported. Interface defects and defect density in different inserted layers have also been reported in this study as they can play a crucial for the device performance. Insertion of ZnO layer and CdS buffer layers have shown improved device performance and PCE. Current investigations may prove to be useful for designing and fabrication of climate friendly, non-toxic and highly efficient solar cells.

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Improving the stabilities of organic solar cells via employing a mixed cathode buffer layer

The European Physical Journal Applied Physics ◽

10.1051/epjap/2021210151 ◽

2021 ◽

Vol 95 (3) ◽

pp. 30201

Author(s):

Xi Guan ◽

Yufei Wang ◽

Shang Feng ◽

Jidong Zhang ◽

Qingqing Yang ◽

...

Keyword(s):

Thin Film ◽

Thermal Stability ◽

Solar Cells ◽

Mixed Layer ◽

Organic Solar Cells ◽

Buffer Layers ◽

Commercial Development ◽

Conversion Efficiencies ◽

Thermal Stability Of ◽

Cathode Buffer Layers

Organic solar cells (OSCs) have been fabricated using cathode buffer layers based on bathocuproine (BCP) and 4,4'-N,N'-dicarbazole-biphenyl (CBP). It is found that despite nearly same power conversion efficiencies, the bilayer of BCP/CBP shows increased thermal stability of device than the monolayer of BCP, mostly because upper CBP thin film stabilizes under BCP thin film. The mixed layer of BCP:CBP gives slightly decreased efficiency than BCP and BCP/CBP, mostly because the electron mobility of the OSC using BCP:CBP is decreased than those using BCP and BCP/CBP. However, the BCP:CBP increases thermal stability of device than BCP and BCP/CBP, ascribed to that the BCP and CBP effectively inhibit reciprocal tendencies of crystallizations in the mixed layer. Moreover, the BCP:CBP improves the light stability of device than the BCP and BCP/CBP, because the energy transfer from BCP to CBP in in the mixed layer effectively decelerates the photodegradation of BCP. We provide a facial method to improve the stabilities of cathode buffer layers against heat and light, beneficial to the commercial development of OSCs.

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