Analysis of phase separation in InGaN epitaxy for advanced solar cells

Due to providing a wide direct-band gap, the III-nitride material system has become crucial for high-efficiency photovoltaic. But phase separation, great challenge for the growth of InxGa1−xN epitaxy, tends to reduce the short circuit current as well as pin down the open circuit voltage. On the basis of this obligation, a mathematical modelling of growthrate for the growth of phase separation free InxGa1−xN epitaxy has been developed showing the dependency of growthrate on growth temperature and pressure, precursor flowrate and molar ratio. This model is considered for InxGa1−xN epitaxy on GaN template on sapphire (Al2O3) substrate with an Indium mole fraction up to 0.4 by Metal Organic Vapor Phase Epitaxy (MOVPE).The results obtained from this model have been compared with experimentally obtained data. Finally, a phase diagram has been interpreted explaining the dependency of growthrate on group-III flowrate, V/III ratio, molar ratio and growth temperature for InxGa1−xN epitaxy under the evolution of indium incorporation.