Synthesis and photovoltaic characteristic of n-type CdSe nanobelts

Abstract

High quality n-type CdSe nanobelts (NBs) were synthesized via the chemical vapor deposition (CVD) method in a Cd-enriched atmosphere. CdSe NB field-effect transistors (FETs) and CdSe NB/p-Si heterojunction devices were fabricated and studied. The n-type conductivity of CdSe NBs was confirmed by nanoFETs based on individual NBs. The heterojunction devices were constructed with the n-type CdSe NBs and p-type bulk Si with 100 nm thickness SiO 2 . Typically, the heterojunction device exhibits an excellent rectifying behavior in the dark with a rectification ratio greater than 10 3 within ±3 V, and photovoltaic effect with an open-circuit photovoltage ( V OC ) of about 0.67 V, a short circuit current ( I SC ) of about 5.88 nA, and an energy conversion efficiency of 1.41%, and shows excellent environmental stability when placed in air for more than 3 months. This study demonstrates a convenient and low-cost method to construct CdSe NBs/Si heterojunction devices, which can be extended to the study of other semiconductor nanomaterials. It is expected that the heterojunction devices will have a great potential for future applications of optoelectronic integration. (a) Schematic illustration of fabricating CdSe NB/Si heterojunction device. (b) Rectification characteristics of the CdSe NB/Si heterojunction measured in the dark. (c) Photovoltaic characteristics of the CdSe NB/Si heterojunction measured under AM 1.5 G illumination. ► High quality n-type CdSe nanobelts (NBs) were synthesized. ► CdSe NB FETs and CdSe NB/p-Si PV devices were fabricated and studied. ► Energy conversion efficiency of the CdSe heterojunction PV device is 1.41%. ► The devices show excellent environmental stability for more than 3 months.