UV/Near-IR dual band photodetector based on p-GaN/${$$\backslash$alpha$}$-In2Se3 heterojunction

 In this report,we demonstrate dual band vertical heterojunction photodetector realized by integrating α-In2Se3 with p-type GaN. Flakes of ~ 110 nm thickness were exfoliated on MOCVD grown p-GaN on silicon substrate. Devicesshowed two distinct detection peaks in spectral responsivity, one at 365 nm and another at 850 nm, corresponding to band edges of GaN and α-In2Se3respectively,with considerable rejection in visible spectrum. Normalised responsivity values were found out to be ~70 mA/W at both 365 nm and850 nmforthebias of -3Valong with photo-to-dark current ratio of ~665 and ~75 in that order. The Devices also showedfasttransient responsewith no persistent photoconductivity (PPC). Thespecific detectivity values estimated were ~1011Jones and ~1010Jones corresponding to illumination at 365 nm and 850 nm respectively.A good linearity of ~0.4 was observed in power dependent analysis of spectral responsivity at 365 nm. The device performance, post annealing was also studied.This study is expected to pave way for new type of optoelectronicdevices by integrating direct bandgap layered material like α-In2Se3and wide bandgap semiconductors