Characterisation of n-type γ-CuCl on Si for UV optoelectronic applications

摘要

The use of co-evaporation of ZnCl_2 with CuCl in order to achieve n-type conductivity in CuCl is reported herein. Linear current-voltage (IV) characteristics in the range of ±4 V have been measured using Cu-Au electrical contacts. Room temperature Hall effect measurements show some evidence of a mixed conduction mechanism. On average the samples exhibit n-type conductivity with a bulk electron carrier concentration n ～1 × 10~(16) cm~(-3) and Hall mobility μ ～ 29 cm~2v~(-1)s~(-1) for a CuCl sample doped with a nominal 3 mole % ZnCl_2. By use of an in situ CaF_2 capping layer, transmission > 90% is achieved. At room temperature a strong Z_3 free excitonic emission occurs at ～385 nm using both photoluminescence and x-ray excitedrnoptical luminescence, indicating the high optical quality of the doped material.