A novel double absorber solar cell configuration achieved over 30% efficient PSCs

An international team of researchers from Bangladesh, USA and Saudi Arabia recently developed a structure that combines a double perovskite absorber layer (DPAL) of Ca₃NCl₃ and Ca₃SbI₃ with an electron transport layer (ETL) and hole transport layer (HTL) of CdS and CBTS via SCAPS-1D.

The team's research demonstrated that the perovskite solar cell (PSC) with DPAL performs much better with the addition of HTL and is more efficient than single-layer PSCs. This work thoroughly examines the effect of thickness, doping levels, and defect densities of each layer on electrical parameters like VOC, JSC, FF, and PCE.

The team explained that the main objective of integrating two absorber layers was to increase the absorbance range of PSCs in order to induce hybridization. The scientists intended to analyze a novel PSC prototype that has never been investigated before.

Using the SCAPS-1D modelling program, a unique DPAL solar cell incorporating HTL was built and simulated. It had two absorber layers: the superior absorber, Ca₃NCl₃, and the inferior absorber, Ca₃SbI₃. The key parameters influencing the simulation performance of this prototype are doping concentrations, defect densities, and absorber layer thicknesses. A thorough investigation was conducted into how these parameters affect the electrical properties of the model. The team also investigated the effects of temperature variations, absorption coefficients, generation and recombination rate, and J-V and QE properties on the electrical performance of the novel PSC prototype based on Ca₃SbI₃/Ca₃NCl₃.

Additionally, it shows the J-V and QE characteristics and thoroughly examines the effects of temperature.

With a DPAL of 24.43 %, two solar cells built around a single absorber achieved a maximum efficiency of 17.19% and 18.07%, respectively. Using CBTS HTL with Al/FTO/CdS/dual absorber Ca₃SbI₃/Ca₃NCl₃)/CBTS/Ni structure, this study achieved an optimized efficiency of up to 30.22% with VOC of 1.39 V, FF of 88%, and JSC of 24.75 mAcm⁻².