TY - JOUR
T1 - Impact on photon-assisted charge carrier transport by engineering electrodes of GaN based UV photodetectors
AU - Aggarwal, Neha
AU - Krishna, Shibin
AU - Jain, Shubhendra Kumar
AU - Arora, Arzoo
AU - Goswami, Lalit
AU - Sharma, Alka
AU - Husale, Sudhir
AU - Gundimeda, Abhiram
AU - Gupta, Govind
N1 - Funding Information:
The authors would like to acknowledge Director, CSIR-NPL India for his constant support. The work is financially supported by the Department of Science and Technology (Govt. of India) under grant aid DST/TM/CERI/C245(G) . Authors also acknowledge Dr. K. K. Maurya for carrying out HRXRD measurements, Mr. Kuldeep and Mr. Prashant Singh for contact fabrication. Neha would like to thank CSIR for providing financial support under CSIR -Research Associateship.
Funding Information:
The authors would like to acknowledge Director, CSIR-NPL India for his constant support. The work is financially supported by the Department of Science and Technology (Govt. of India) under grant aid DST/TM/CERI/C245(G). Authors also acknowledge Dr. K. K. Maurya for carrying out HRXRD measurements, Mr. Kuldeep and Mr. Prashant Singh for contact fabrication. Neha would like to thank CSIR for providing financial support under CSIR-Research Associateship.
Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2019/5/15
Y1 - 2019/5/15
N2 - 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.
AB - 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.
KW - Electrode engineering
KW - GaN
KW - PAMBE
KW - Photoresponsivity
KW - Visible-blind photodetector
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U2 - 10.1016/j.jallcom.2019.01.198
DO - 10.1016/j.jallcom.2019.01.198
M3 - Article
AN - SCOPUS:85060539398
VL - 785
SP - 883
EP - 890
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
SN - 0925-8388
ER -