Ultra-High Responsivity and Enhanced Trap Assisted Charge Transfer by utilizing Ti3C2TX(MXene) as a Transport Layer for ReS2 based Flexible Broadband Photodetector: A better Alternative to Graphene

Abstract

Even though there are many reports on low-cost flexible broadband photodetector the main issue is the low value of the responsivity due to non-uniformity of the substrate. The reason is the lack of suitable transport material. Graphene has proven to be the best till date, but, on unconventional substrates such as biodegradable paper, responsivity values still remain an unresolved issue. This report demonstrates for the first time the use of Ti3C2TX(MXene) as transport layer, utilizing 2D ReS2 as active material on paper substrate as broadband photodetector and further compared its performance with graphene. Responsivity values calculated for ReS2/MXene and ReS2/graphene under visible and NIR illumination are 40.8 AW−1, 26.9 AW−1, and 26.5 AW−1, 17.5 AW−1, respectively, which suggests that MXene as transport layer largely enhances performance. To understand the phenomena, detailed mechanisms studies are presented in terms of density of surface states and energy band diagram. Surface states density was found to be larger in MXene compared to graphene structure, suggests that the lifetime of the carrier is high with MXene as transport layer compared to Graphene due to trap assisted charge transfer. This ReS2/MXene heterostructure based environment friendly photodetector can find potential applications in future flexible optoelectronics.