Fig. 9
From: Low-Cost Flexible ZnO Microwires Array Ultraviolet Photodetector Embedded in PAVL Substrate
a The band diagram for an unbent MW: the conduction and valence band edges are bent near the surface due to the surface pinning of Fermi level. The intrinsic surface recombination barrier ɸi is also shown. b The case for a bent MW: the piezo-induced electric field lowers the surface recombination barrier from ɸi to ɸb