On the Uniqueness of Ideality Factor and Voltage Exponent of Perovskite-Based Solar Cells.
Perovskite-based solar cells have attracted much recent research interest with efficiency approaching 20%. While various combinations of material parameters and processing conditions are attempted for improved performance, there is still a lack of understanding in terms of the basic device physics and functional parameters that control the efficiency. Here we show that perovskite-based solar cells have two universal features: an ideality factor close to two and a space-charge-limited current regime. Through detailed numerical modeling, we identify the mechanisms that lead to these universal features. Our model predictions are supported by experimental results on solar cells fabricated at five different laboratories using different materials and processing conditions. Indeed, this work unravels the fundamental operation principle of perovskite-based solar cells, suggests ways to improve the eventual performance, and serves as a benchmark to which experimental results from various laboratories can be compared.
†Department of Energy Science and Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
Sumanshu
S
Agarwal
‡School of Physics, Indian Institute of Science Education and Research, Thiruvananthapuram 695016, Kerala, India.
Madhu
M
Seetharaman
§Department of Physics, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
Naresh K
NK
Kumawat
†Department of Energy Science and Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
Anand S
AS
Subbiah
†Department of Energy Science and Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
Shaibal K
SK
Sarkar
§Department of Physics, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
Dinesh
D
Kabra
‡School of Physics, Indian Institute of Science Education and Research, Thiruvananthapuram 695016, Kerala, India.
Manoj A G
MA
Namboothiry
∥Department of Electrical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
Pradeep R
PR
Nair
dark IV; organic–inorganic halide; photovoltaics; recombination; space charge limited transport