posted on 2020-03-31, 19:04authored byHarshavardhan Gaonkar, Junhao Zhu, Ranjith Kottokkaran, Behrang Bhageri, Max Noack, Vikram Dalal
We report on thermally
stable inorganic mixed halide perovskite
solar cells deposited using a vapor deposition technique with no loss
in device performance at 200 °C for 72 h. X-ray diffraction analysis
confirms no compositional degradation of the perovskite layer up to
200 °C anneals. We use a layer-by-layer vapor deposition technique
with thin layers (several nanometers) of PbI2 and CsBr
precursors to fabricate inorganic mixed halide perovskite solar cells
with a photoconversion efficiency of 11.8%. We study the effect of
several key parameters of the perovskite fabrication process that
control the intermixing of the perovskite layer and their effect on
device efficiency and hysteresis. The thermal stability of the perovskite
material and its energy band gap of 1.87 eV makes it appropriate for
use in tandem junction cells for use in real-life environments with
high solar illuminance where the ambient temperatures exceed 55 °C
in the summer, and silicon cell module temperatures approach 86 °C.