Impact on photon-assisted charge carrier transport by engineering electrodes of GaN based UV photodetectors

Neha Aggarwal, Shibin Krishna, Shubhendra Kumar Jain, Arzoo Arora, Lalit Goswami, Alka Sharma, Sudhir Husale, Abhiram Gundimeda, Govind Gupta

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)


A scheme illustrating electrode-engineering in metal-semiconductor-metal geometry is employed for fabricating GaN-based high-performance ultraviolet photodetectors. The effect of different metal-semiconductor (Au, Ti/Al and Al) junctions on photon-assisted charge-carrier transport and the current-conduction is explored. Depending upon work function of the metals, barrier height varies which contributed towards different characteristics of the device revealing linear and non-linear behaviour of the electrical measurements from the non-rectifying and rectifying contact at the metal-semiconductor interface respectively. A maximum photoresponsivity & efficiency of 280.4 mA/W and 107.04% respectively, under 5 V applied bias in the visible-blind region was measured from the device with rectifying Au electrodes. While, the photoresponsivity values of 219 mA/W and 200 mA/W under the same bias has been achieved from devices measured with near-Ohmic contacts using Ti/Al and Al electrodes, respectively. The enhancement in detector's performance with Au electrode has been attributed to the built-in electric field as well as the presence of internal gain which can promote efficient transport of charge carriers through the metal-semiconductor interface. Thus, an approach has been adopted to enhance the photoresponsivity of the fabricated GaN-based optoelectronic devices which could be utilized for wide range of industrial, military, environmental and biological applications.

Original languageEnglish
Pages (from-to)883-890
Number of pages8
JournalJournal of Alloys and Compounds
Publication statusPublished - 2019 May 15
Externally publishedYes


  • Electrode engineering
  • GaN
  • Photoresponsivity
  • Visible-blind photodetector

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry


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