Self-Powered UV-B Photodetector Based on Hybrid Al:MgZnO/PEDOT:PSS Schottky Diode

Wide bandgap Al-doped MgZnO (AMZO) films with a Mg content up to 47.5% were prepared on sapphire substrates. Conductivities of the AMZO films were greatly improved through zinc vapor annealing. Vertical structure photodiodes were fabricated by introducing poly (3, 4-ethylenedioxythiophene) poly (styrenesulfonate) (PEDOT:PSS) as a Schottky contact. The photodiode showed characteristics response to the UV-B light, with a peak responsivity of 19.1 mA/W at 278 nm and a visible rejection ratio of over two orders without external bias. The high performance was attributed to the high conductivity of the AMZO film and good Schottky contact formed using PEDOT:PSS.