۱- Introduction

۲- Experimental

۳- Results and discussion

۴- Conclusions

References

Abstract

Organic/inorganic lead halide perovskite solar cells have recently attracted much attention in photovoltaic research, due to the devices show promising ways to achieve high efficiencies. The perovskite devices with high efficiencies, however, are typically fabricated in tandem solar cell which is complicated. In this research work, we introduce a solar cell device with the combination of CH3NH3PbI3−xClx perovskite and bulk heterojunction PCDTBT:PC70BM polymer without any tandem structure. The new integrated perovskite/polymer hybrid structure of ITO/PEDOT:PSS/perovskite/PCDTBT:PC70BM/PC70BM/TiOx/Al provides higher power conversion efficiency (PCE) of devices compared with conventional perovskite cell structure. With the optimized PCDTBT:PC70BM thickness of ∼۷۰ nm, the highest PCE of 11.67% is achieved. Variation of conducting donor polymers in this new structure is also preliminary demonstrated. This study provides an attractively innovative structure and a promising design for further development of the new-generation solar cells.

Introduction

Solar energy is one choice of interesting renewable energies, because it has lower environmental impact compared with fossil fuels [1]. Solar cells or photovoltaic devices can directly convert solar radiation into electricity. Currently, the commercially accessible crystalline silicon (Si) solar cells have shown PCE up to 25%, but these cells are still produced by complex methods at quite high temperatures [2]. Therefore, many researchers have tried to find new photovoltaic materials to produce alternative solar cells, which expose high performance with large scale production and low cost [3]. Organic-inorganic hybrid material, named perovskite, as a new light absorber has been attracted considerable interest, because of their great properties for the development of low-cost thin-film solar cells [4]. The perovskite material performs high absorption coefficients, suitable direct band gaps, small exciton binding energies, high carrier mobilities, long diffusion lengths, and superior defect tolerances [1–۵]. The structure of perovskite material is ABX3, which A is cation (metal or hydrocarbon), B is a metal cation, and X is halide atoms. Examples of perovskite are organometallic halide perovskites, e.g. CH3NH3PbI3 and CH3NH3PbI3−xClx [5]. Nowadays, devices with combination of two or more completed photovoltaic layers in one cell, called tandem cells, have been expected to get high efficiency with the cells connected in series, which absorb light in different wavelength ranges. Giles et al. [6] exhibited an infrared absorbing wider bandgap FA0.83Cs0.17Pb(I0.5Br0.5)3 material in two and four-terminal perovskite/perovskite tandem solar cells, which achieved in 17.0% and 20.3%, respectively. This infrared absorbing perovskite material also showed excellent thermal and atmospheric stability. Reza et al.