Effects of Cs-doping on morphological, optical and electrical properties of Bi2Te3 nanostructures

• Cs-doped Bi2Te3 nanostructures were synthesized by a solvothermal route at 100 °C.
• EDX analysis confirmed the elemental purity of the nanostructures.
• The direct band gap for the doped sample was found to be 2.30 eV.
• The doped sample shows the enhancement of current by 3 orders of magnitude (μA–mA).

A new approach for doping of cesium atoms in Bi2Te3 nanostructures using the inexpensive solvothermal route at a temperature of 100 °C is presented. X-ray diffraction (XRD) pattern, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), UV–vis spectral studies and electrical studies (I–V measurements) were carried out for both pure Bi2Te3 and Cs-doped Bi2Te3 nano-samples. The experimental outcome shows that the 2 at.% doping of cesium results in the decrement of band gap and significant enhancement of the current by 3 orders of magnitude. The experimental observations also show that the doping effect of Cesium ions in Bi2Te3 nanostructures changes the linear behavior of I–V curve.