Thin Film GaAs Devices on Epi-Ready Metal Substrates for Flexible Photovoltaics and Flexible Electronics

Single-crystalline-like thin film GaAs has been grown on epi-ready germanium-buffered flexible metal substrates. The GaAs on flexible substrate has been used to fabricate flexible photovoltaic and flexible photodetector devices. Flexible GaAs photovoltaics on inexpensive substrate addresses the problem with the exorbitant cost of GaAs single crystal wafers that have been used so far. Efficiency levels up to 13.1% have been achieved with GaAs on metal substrate. A 360° field of view is feasible with flexible GaAs photodetectors that is not possible with rigid formats. A responsivity value of 0.8 A/W was obtained at 830 nm that is on par with commercial GaAs photodetectors. The flexible GaAs photodetector exhibits short rise and fall times (less than 0.2 ms), good reproducibility and fully-reversible switching ability. Thin film GaAs on flexible substrates can open up a wide range of applications in flexible electronics where high performance, high power or operation in extreme environments is needed and not feasible with polymer-based flexible electronics.