Colloquia

Summary

In the past recent years, perovskite solar cells have shown promising results in power conversion efficiencies while maintaining a low-cost fabrication [1]. NiOx is a hole transport layer, where, in a p-i-n PSC configuration, it is deposited on top of the TCO/glass substrate followed by the absorber layer and the electron transport layer.

While multiple techniques can be used to deposit NiOx, we use pulsed laser deposition (PLD) to deposit NiOx layers. PLD offers a wide variety of deposition parameters to control the crystallinity, optical and electrical properties of NiOx. Therefore the properties of PLD-NiOx and their role in the perovskite solar cells are studied in this thesis. Also, it has been reported that the low conductivity of NiOx, and surface traps at the NiOx/perovskite layers, can limit the associated perovskite solar cells performance [2]. On the other hand, doping NiOx has been shown to be an effective method to improve its hole mobility and tune its work function [3].

Consequently, this project also explores the effect of K doping of NiOx on its crystal structure, morphology, optical, and electronic properties. The optoelectronic properties of K-doped NiOx are also tested in perovskite solar cells.

1. Sajid, S. et al. Breakthroughs in NiOx-HTMs towards stable, low-cost and efficient perovskite solar cells. Nano Energy 51, 408–424 (2018).

2. Zheng, X. et al. Interface modification of sputtered NiO x as the hole-transporting layer for efficient inverted planar perovskite solar cells. Journal of Materials Chemistry C 8, 1972–1980 (2020).

3. Yang, M., Pu, H., Zhou, Q. & Zhang, Q. Transparent p-type conducting K-doped NiO films deposited by pulsed plasma deposition. Thin Solid Films 520, 5884–5888 (2012).