Effects of Deposition Temperature and Working Pressure on the Thermal and Nanomechanical Performances of Stoichiometric Cu3N: An Adaptable Material for Photovoltaic Applications

Abstract

The pursuit of efficient, profitable, and ecofriendly materials has defined solar cell research

from its inception to today. Some materials, such as copper nitride (Cu3N), show great promise for

promoting sustainable solar technologies. This study employed reactive radio-frequency magnetron

sputtering using a pure nitrogen environment to fabricate quality Cu3N thin films to evaluate how

both temperature and gas working pressure affect their solar absorption capabilities. Several characterization

techniques, including X-ray diffraction (XRD), Rutherford backscattering spectrometry

(RBS), Raman spectroscopy, scanning electron microscopy (SEM), nanoindentation, and photothermal

deflection spectroscopy (PDS), were used to determine the main properties of the thin films.

The results indicated that, at room temperature, it is possible to obtain a material that is close to

stoichiometric Cu3N material (Cu/N ratio 3) with (100) preferred orientation, which was lost as

the substrate temperature increases, demonstrating a clear influence of this parameter on the film

structure attributed to nitrogen re-emission at higher temperatures. Raman microscopy confirmed

the formation of Cu-N bonds within the 628–637 cm􀀀1 range. In addition, the temperature and the

working pressure significantly also influence the film hardness and the grain size, affecting the elastic

modulus. Finally, the optical properties revealed suitable properties at lower temperatures, including

bandgap values, refractive index, and Urbach energy. These findings underscore the potential of

Cu3N thin films in solar energy due to their advantageous properties and resilience against defects.

This research paves the way for future advancements in efficient and sustainable solar technologies