Stable and Efficient Graded MA0.83Cs0.17Pb(I0.83Br0.17)3 Alloy Thin Film‐Based Inverted‐Type Perovskite Solar Cells

摘要

The surface morphologies, crystallinities, and excitonic characteristics of MAxCs1?xPb(IxBr1?x)3 thin films deposited on top of the P3CT‐Na/ITO/glass substrates are investigated by using the atomic‐force microscopic images, absorbance spectra, grazing incidence X‐ray diffraction patterns, photoluminescence (PL) spectra, and Raman scattering spectra. The P3CT‐Na‐based perovskite solar cell shows a stable and efficient maximum power density curve due to the formation of a graded MA0.83Cs0.17Pb(I0.83Br0.17)3 alloy thin film which is confirmed by using the surface‐sensitive PL and Raman scattering spectra. The highest power conversion efficiency (PCE) of the P3CT‐Na‐based MA0.83Cs0.17Pb(I0.83Br0.17)3 solar cells is 15.93 mainly due to the high fill factor of 79.4. Besides, the PCE of the nonencapsulated solar cell slowly decreases to a moderate value (10.48) within 157?days under an uncontrolled environment (55–60 relative humidity) at room temperatures (22–25?°C).