In situ Study of p-NiO Film Quality at High Temperatures up to 1100 deg C

TL;DR

This study uses in situ high-temperature X-ray diffraction to investigate the structural evolution and phase changes of NiO thin films up to 1100°C, revealing how temperature affects crystallinity and electrical resistivity.

Contribution

It provides the first detailed in situ analysis of NiO film phase evolution at high temperatures, linking structural changes to electrical properties.

Findings

NiO crystallizes from amorphous to cubic phase between 300-400°C

Resistivity increases with crystallinity and phase changes

Ni2O3 formation occurs at 1100°C, increasing resistivity

Abstract

NiO is a promising p-type material for photovoltaics and power electronics, but its temperature limits remain unclear. Using in situ high-temperature X-ray diffraction (HT-XRD) from 30 to 1100 C, we track the structural evolution of NiO thin films in air. The film crystallizes from an amorphous phase to cubic NiO between 300 and 400 C, where the emergence and growth of the (111) diffraction peak correlate with an increase in electrical resistivity. Further increases in temperature lead to improved crystallinity and higher resistivity. At 1100 C, the formation of Ni2O3 is observed, resulting in a highly resistive film. This study establishes a clear correlation between phase evolution, crystallinity, and resistive behavior in NiO thin films.