A charge inverter for III-nitride light-emitting diodes

作者：Zhang, Zi-Hui; Zhang, Yonghui; Bi, Wengang; Geng, Chong; Xu, Shu^*; Demir, Hilmi Volkan^*; Sun, Xiao Wei^*

来源：Applied Physics Letters, 2016, 108(13): 133502.

DOI：10.1063/1.4945257

• QUANTUM BARRIER
• HOLE TRANSPORT
• EFFICIENCY

In this work, we propose a charge inverter that substantially increases the hole injection efficiency for InGaN/GaN light-emitting diodes (LEDs). The charge inverter consists of a metal/electrode, an insulator, and a semiconductor, making an Electrode-Insulator-Semiconductor (EIS) structure, which is formed by depositing an extremely thin SiO2 insulator layer on the p(+)-GaN surface of a LED structure before growing the p-electrode. When the LED is forward-biased, a weak inversion layer can be obtained at the interface between the p(+)-GaN and SiO2 insulator. The weak inversion region can shorten the carrier tunnel distance. Meanwhile, the smaller dielectric constant of the thin SiO2 layer increases the local electric field within the tunnel region, and this is effective in promoting the hole transport from the p-electrode into the p(+)-GaN layer. Due to the improved hole injection, the external quantum efficiency is increased by 20% at 20mA for the 350 x 350 mu m(2) LED chip. Thus, the proposed EIS holds great promise for high efficiency LEDs.

• 出版日期2016-3-28
• 单位河北工业大学; 南方科技大学