Thermalisation rate study of GaSb-based heterostructures by continuous wave photoluminescence and their potential as hot carrier solar cell absorbers

GaSb-based heterostructures are tested as candidates for a hot carrier solar cell absorber. Their thermalisation properties are investigated using continuous wave photoluminescence. Non-equilibrium carrier populations are detected at high excitation levels. An empirical expression of the power lost by thermalisation is deduced from the incident power dependent carrier temperature. The experimentally determined thermalisation rate is then used to simulate the potential efficiency of a hot carrier solar cell, showing a significant efficiency improvement compared to a fully thermalised single p-n junction of similar bandgap.