One-step synthesis of CdSe nanotubes with novel hollow tubular structure as high-performance active material for photodetector

Abstract

Cadmium selenide (CdSe) nanotubes have been successfully synthesized via one-step thermal evaporation process without using any templates. The morphology and crystalline structure of the CdSe nanotubes have been characterized, demonstrating the CdSe nanotubes with novel hollow tubular architecture are single-crystalline and grow along the [0002] direction. Furthermore, the single-crystalline CdSe nanotubes are first utilized as active layer to fabricate a metal-semiconductor-metal (MSM) nanostructured photodetector with Ag nanowires network as transparent electrodes. The CdSe nanotubes-based photodetector exhibits enhanced performance among CdSe nanostructure- and CdSe nanostructure heterostructures-based photodetectors reported so far, such as high photoresponsivity (Rλ≈76 A/W), large photoconductive gain (G ˜ 190) and low operation voltages (1 V). The enhanced performance can be attributed to the perfect hollow tubular architecture of CdSe nanotubes and the Schottky contacts between Ag and CdSe. In addition, the comparative studies of the CdSe nanotubes-based photodetetor in air and in vacuum are investigated.