Generic Model of SH-LED for Mid-infrared (2-5µm) Applications

In this paper, we present a physics based model of a P⁺ -InAs_0.36Sb_0.20P_0.44/ n⁰ -InAs/n -InAs single heterostructure light emitting diode (SH-LED) suitable for use as source in gas detection and futuristic optical fiber communication systems in the mid-infrared spectral region at 300 K. The model takes into account all dominating radiative and non-radiative recombination processes, interfacial recombination and self-absorption in the active layer of the SH-LED structure. The effect of various recombination mechanisms on the quantum efficiency, modulation bandwidth and output power of the LED has been evaluated. The proposed SH- LED has been studied for its utility in mid-infrared optical fiber communication by considering the modulation bandwidth and its variation with active layer width of the SH-LED structure. The I-V characteristic of the SH-LED has been evaluated and cut-in voltage found to be 0.26 V. The output power of the SH-LED has been computed as a function of bias current and it is found to be in good agreement with the reported experimental results.