Fig. 4
Schematic band diagrams of a CuI/ZnO heterojunction a without and b with compressive strain to illustrate the working mechanism of piezo-phototronic effect-enhanced PD performance; c photocurrent ΔI, d photoresponsivity R, and e relative changes of photoresponsivity R/R 0 and f the detectivity D* of CuI/ZnO PD under different strain and illumination conditions, biased at 1.5 V