Dilute Nitride InGaAsN and GaAsSbN Layers Grown by Liquid-Phase Epitaxy for Photovoltaic Applications

Dilute nitride InGaAsN and GaAsSbN layers are grown by low-temperature liquid-phase epitaxy (LPE) on GaAs substrates and characterized in view of application in solar cells. The composition of the layers is determined by energy-dispersive X-ray spectroscopy. X-ray photoelectron spectroscopy measurements confirm the Sb content and provide information about the chemical bonding of the N atoms. The band gap values at room temperature assessed from surface photo-voltage and photoluminescence measurements are in good agreement. The experimental results show that the layers exhibit reproducible properties, including a good optical quality and a photosensitivity red limit extended in comparison to GaAs down to about 1.33 – 1.37 eV for InGaAsN and 1.19 – 1.23 eV for GaAsSbN layers. The results obtained highlight the capacity of the LPE for growing dilute nitride layers with good optical quality for photovoltaic applications.