Comparative performance analysis of InGaN/GaN multi-quantum-well light-emitting diodes with p- and n-type step-doped barriers

• DOI: 10.1007/s10825-016-0838-x
• Publication Date: 2016-06-13T05:56:36Z
• Authors: Sumitra Singh; Pranav Utpalla; Suchandan Pal; Chenna Dhanavantri
• Keywords: 02 engineering and technology; 0210 nano-technology; 7. Clean energy

The performance of InGaN/GaN light-emitting diodes (LEDs) with multiple-quantum-well barriers formed from alternating p- and undoped regions is compared with that of reference devices having similar epilayer structure but with barriers formed from alternating n- and undoped regions. Simulations verify that p-type step-doping in the quantum barriers is more effective in reducing the polarization-induced electric field and lowering the energy barrier for hole transport as well as increasing the barrier height of the conduction band to confine electrons, thereby enhancing the radiative recombination rate compared with n-type step doping in the quantum barriers. This profile also increments hole injection and provides a more uniform carrier distribution across the multiple quantum wells. According to the simulation results, when using the alternating stepwise doping profile in the barrier regions in the proposed structure, the internal quantum efficiency is remarkably improved, offering dual advantages of a homogeneous hole distribution due to the undoped region and a reduced valence-band barrier height due to the p-doping.