• 文献标题:   Simulation on effect of metal/graphene hybrid transparent electrode on characteristics of GaN light emitting diodes
  • 文献类型:   Article
  • 作  者:   QIAN MC, ZHANG SF, LUO HJ, LONG XM, WU F, FANG L, WEI DP, MENG FM, HU BS
  • 作者关键词:   finite element method, graphene, temperature distribution, transmittance, lightemitting diode
  • 出版物名称:   CHINESE PHYSICS B
  • ISSN:   1674-1056 EI 1741-4199
  • 通讯作者地址:   Chongqing Univ
  • 被引频次:   1
  • DOI:   10.1088/1674-1056/26/10/104402
  • 出版年:   2017

▎ 摘  要

In order to decrease the Schottky barrier height and sheet resistance between graphene (Gr) and the p-GaN layers in GaN-based light-emitting diodes (LEDs), some transparent thin films with good conductivity and large work function are essential to insert into Gr and p-GaN layers. In this work, the ultra-thin films of four metals (silver (Ag), golden (Au), nickel (Ni), platinum (Pt)) are explored to introduce as a bridge layer into Gr and p-GaN, respectively. The effect of a different combination of Gr/metal transparent conductive layers (TCLs) on the electrical, optical, and thermal characteristics of LED was investigated by the finite element methods. It is found that both the TCLs transmittance and the surface temperature of the LED chip reduces with the increase of the metal thickness, and the transmittance decreases to about 80% with the metal thickness increasing to 2 nm. The surface temperature distribution, operation voltage, and optical output power of the LED chips with different metal/Gr combination were calculated and analyzed. Based on the electrical, optical, and thermal performance of LEDs, it is found that 1.5-nm Ag or Ni or Pt, but 1-nm Au combined with 3 layered (L) Gr is the optimal Gr/metal hybrid transparent and current spreading electrode for ultra-violet (UV) or near-UV LEDs.