Modeling the capacitance-voltage characteristics of AlGaN-based UV-C LEDs.

We propose a detailed approach for modeling the C-V characteristic of complex heterostructure-based devices, investigating the case of UV-C LEDs. The study is based on combined experimental measurements and TCAD simulations, and explores: i) the impact of defects at critical interfaces on the apparent charge profile; ii) the dependence of the C-V characteristic on the efficiency of carrier injection toward the QWs; iii) the impact of a non-ideal partially-rectifying p-contact on the C-V curves. By accounting for these processes and non-idealities, we were able to achieve a good reproduction of the experimental C-V characteristic and of the corresponding apparent charge profile. The result presented in this paper provide relevant information for the investigation of specific device features, based on simple electrical characterizations.