Ideality Factor Based Computational Analysis of Perovskite Solar Cells

Abstract

Photovoltaic semiconductors are diodes which produce a current when exposed to light. The ideality factor is a parameter which tells how closely a semiconductor behaves to an ideal diode. In an ideal diode, the only mechanism for hole electron recombination is direct bimolecular recombination. Because there are multiple mechanisms of recombination, there are no real devices with a perfect ideality factor. The types of recombination occurring within a device can be inferred by its ideality factor. In this work, we examine the ideality factor of perovskite solar cells to identify possible recombination mechanisms in the device. Analyzing fabricated perovskite solar cells using their ideality factor can indicate which type of recombination is dominant in the device. The interaction between the perovskite crystal and transport layers is of high interest as differentials in energy band can hinder overall power conversion efficiency and act as a site for nonradiative recombination loss. We show that measuring the ideality factor of high performing cells and correlating the recombination mechanisms inferred can positively drive the electrochemistry of fabricating these devices. Thereby driving researchers to maximize or minimize types of recombination for optimization.