Hot Carrier Dynamics In Nitrogen - Rich Hafnium Nitride Thin Film

Hafnium nitride with rock - salt structure (HfN) is a suitable material for the hot carrier solar cell (HCSC) absorber, primarily due to wide phonon band gap. Nitrogen - rich phase of hafnium nitride crystallizes in cubic Th3P4 structure and is a semiconductor. Here, we have synthesized nitrogen - rich c-Hf3N4 using thermal atomic layer deposition and characterized the hot carrier dynamics with transient absorption (TA) spectroscopy. Fitting of the TA kinetics result in lifetime of the carriers in the order of hundreds of picoseconds. This opens feasibility of nitrogen - rich hafnium nitride to be used in photovoltaic device as an HCSC absorber.