Enhanced electrical and optoelectrical properties of cadmium selenide nanobelts by chlorine doping

Single-crystalline chlorine-doped cadmium selenide (CdSe) nanobelts (NBs) with a wurtzite structure were synthesised by using CdSe and InCl₃ powder as sources via a co-evaporation approach. The investigation of the performance of the field-effect transistors fabricated from Cl-doped NBs shows n-type conduction behaviour and enhanced conductivity (1-70 S/cm). Furthermore, it is found that the photoconductivity (illuminated by a white light with a power density of 1.3 mW/cm²) increases with the enhancement of the conductivity. Photoconductive analysis reveals that the Cl-doped NBs show excellent photoresponse properties, with responsivity of 8.87 × 10⁵ AW^-1 and a corresponding external quantum efficiency of 1.74 × 10⁶ when illuminated under a 650 nm light and biased 1 V. In addition, the electrical properties of the Cl-doped NBs can be influenced by changing the ambiance, which is caused by their surface states.