Direct GaAs Nanowire Growth and Monolithic LightEmitting Diode Fabrication on Flexible Plastic Substrates

The growth of self-catalyzed GaAs nanowires (NWs) and monolithic light-emitting diode (LED) directly on flexible plastic substrates is reported. Dense GaAs NW forest is attained in self-catalyzed mode using metalorganic vapor phase epitaxy. The NWs are shown to be crystalline with a zinc-blende phase. The optical properties of the GaAs NWs are found to be promising in both photoluminescence emission and light-trapping based on reflectance and transmittance measurements. The LED is fabricated from p-type NWs by depositing Au as Ohmic contact and TiO2/ITO as an electron-selective contact. The demonstrated NW growth and LED fabrication represent a significant step toward low-cost, industrially feasible flexible III–V NW optoelectronic applications, as plastic is inexpensive, and the fabrication steps are compatible with roll-to-roll processing.