Preparation of controlled ZnO nanostructures and their optical properties

Toward Understanding the Role of VZn Defect on the Photoconductivity of Surface-Passivated ZnO NRs

“…One-dimensional (1D) nanostructures are the most promising materials for various optoelectronic applications ranging from sensing devices to LEDs to solar cells. − The nanorods (NRs) array films offer the most appropriate design which can effectively modulate the optical and electronic characteristics due to availability of their high surface area. One-dimensional nanostructure of different morphologies of ZnO is one of the most studied wide band gap semiconductors ( E gap = 3.36 eV at 300 K) owing to its outstanding physicochemical properties controlled by the surface defects as a result of their high surface to bulk ratio whereas the role of the bulk properties is comparatively negligible. − One such example is very high ultraviolet (UV) response properties of ZnO NRs due to its low photoexcited electron–hole recombinations controlled by its large surface defects. − The photoresponse of ZnO can also be tuned within the visible spectral region by controlling the intrinsic surface defect levels, which makes it an excellent photodetector in the sub-UV regime. Therefore, understanding the behavior of surface defects is essential to the successful application of ZnO as UV and visible photodetector since the surface defects often capture the electron–hole pairs and make the response slow.…”