Self-powered ultraviolet photodetectors based on CuInO2: Ca/GaN epitaxial heterojunction e

In this paper, calcium-doped p-type CuInO2 (CuInO2:Ca) epitaxial films with c axis preferred orientation were grown on n-type GaN (001) substrates by the pulsed laser deposition (PLD) technology, and CuInO2/GaN p-n heterojunction photodetectors were fabricated based on the prepared CuInO2 films. The lattice structure, surface morphology, energy band structure, composition, and electrical properties of the grown CuInO2:Ca films were characterized. Compared with the undoped and Ca-doped (1 at.%) films, the photoresponsivity (R), detectability (D*) and rise (tau r)/decay (tau d) time of the detector based on the CuInO2:Ca (2 at.%)) film with the best crystal quality are 1.13 mA/W, 9.9 x 1010 Jones, and 0.14/0.1 s, under the irradiation of 365 nm (21.5 mW/cm2) UV light with 0 V bias, respectively, and can achieve a maximum R-value of 1.6 mA/W under the lowest light in-tensity (2.4 mW/cm2). The results indicate that the self-powered UV photodetectors based on CuInO2/GaN p-n heterojunctions have potential applications in the field of optoelectronic devices.