The structural, optical and excitonic characteristics of MAxCs1-xPb(IxBr1-x)3 crystal thin films were investigated by using the X-ray diffraction patterns, scanning electron microscopic images, absorbance spectra and photoluminescence (PL) spectra. The time-dependent PL spectra shows that the MA0.8Cs0.2Pb(I0.8Br0.2)3 crystal thin film is a photo-stable light absorbing material, which results in an efficient and stable perovskite solar cell without the additional encapsulation. The highest power conversion efficiency (PCE) of MA0.8Cs0.2Pb(I0.8Br0.2)3 solar cells is 10.02%. In addition, the PCE decreases slowly toward a stable value (5.71%) for more than 120 days under moderate environment conditions (55–60 RH%).
- Stable perovskite solar cells
- Time-dependent photoluminescence