Estimation of the ideality factor of ZnTe/CdTe p-p heterojunction diodes

Direct analytical method for estimating the ideality factor of ZnTe/CdTe isotype p-p heterojunction diodes is reported. The calculations were performed at two temperatures 300 K and 200 K. Simulations, considering the series and shunt parasitics, showed ideality factor values of 6.9 and 22.4 at 300 K and 200 K respectively. These values were compared with those extracted from the dark current-voltage curves which are 6.5 and 28.2 at the same temperatures. The large ideality factor in this system (particularly at low temperature) was attributed to the presence of high density of interface states (typically similar to 10(13) cm(-2)).