Performance Enhancement of All-Inorganic Carbon-Based CsPbIBr2 Perovskite Solar Cells Using a Moth-Eye Anti-Reflector.

Wensheng Lan,Yibing He,Gang Liu,Chunfu Zhang,Qirui Guo,Weidong Zhu,Wenming Chai,He Xi,Peng Dong,Baichuan Tian,Dazheng Chen,Xiaoping Xie

doi:10.3390/nano11102726

Abstract

All-inorganic carbon-based CsPbIBr2 perovskite solar cells (PSCs) have attracted increasing interest due to the low cost and the balance between bandgap and stability. However, the relatively narrow light absorption range (300 to 600 nm) limited the further improvement of short-circuit current density (JSC) and power conversion efficiency (PCE) of PSCs. Considering the inevitable reflectance loss (~10%) at air/glass interface, we prepared the moth-eye anti-reflector by ultraviolet nanoimprint technology and achieved an average reflectance as low as 5.15%. By attaching the anti-reflector on the glass side of PSCs, the JSC was promoted by 9.4% from 10.89 mA/cm2 to 11.91 mA/cm2, which is the highest among PSCs with a structure of glass/FTO/c-TiO2/CsPbIBr2/Carbon, and the PCE was enhanced by 9.9% from 9.17% to 10.08%. The results demonstrated that the larger JSC induced by the optical reflectance modulation of moth-eye anti-reflector was responsible for the improved PCE. Simultaneously, this moth-eye anti-reflector can withstand a high temperature up to 200 °C, and perform efficiently at a wide range of incident angles from 40° to 90° and under various light intensities. This work is helpful to further improve the performance of CsPbIBr2 PSCs by optical modulation and boost the possible application of wide-range-wavelength anti-reflector in single and multi-junction solar cells.

Highlights

Since the first successful preparation by Miyasaka et al [1], organic-inorganic hybrid perovskite solar cells (PSCs) have achieved an explosive increase of power conversion efficiency (PCE) from 3.8 to 25.5% during ten years [2,3,4,5,6,7], closing to the PCE of crystal silicon solar cells, and have been recognized as the next-generation cost-effective photovoltaic technology
To enhance the performance of carbon-based CsPbIBr2 PSCs, we have proposed the intermolecular exchange strategy (CsI treatment) [27], flux-mediated growth strategy (CH3 NH3 Br incorporation) [20], light-processing technology [28], and aged precursor method [27] to grow full-coverage, large-grained, pure-phase CsPbIBr2 films, which boosted the open circuit voltage and record PCE of devices to 1.323 V and 10.82%
Resulted JSC was promoted by 9.4% from 10.89 mA/cm2 to 11.91 mA/cm2, which is the highest among PSCs with a structure of glass/Fluorine-doped tin oxide (FTO)/c-TiO2/CsPbIBr2/Carbon, and the PCE

Summary

Introduction

Since the first successful preparation by Miyasaka et al [1], organic-inorganic hybrid perovskite solar cells (PSCs) have achieved an explosive increase of power conversion efficiency (PCE) from 3.8 to 25.5% during ten years [2,3,4,5,6,7], closing to the PCE of crystal silicon solar cells, and have been recognized as the next-generation cost-effective photovoltaic technology. An effective solution is to replace the organic ions by inorganic ions (e.g., Cs+ and Rb+ ), such as CsPbI3 , CsPbI2 Br, CsPbIBr2 , and CsPbBr3 [10,11,12,13,14], which were called as all-inorganic. CsPbI3 and CsPbI2 Br show a relatively narrow bandgap of about 1.73 and 1.90 eV, the phase instability at room temperature is unfavorable for the long-term operation of PSCs [15,16,17]. CsPbBr3 achieved the best environment stability; the large bandgap (~2.3 eV) limited its light absorption edge to less than 540 nm [18,19]. While the all-inorganic CsPbIBr2 PSCs possess excellent stability under ambient air atmosphere with the controlled relative

Methods

Results

Conclusion