TY - JOUR
T1 - Ultrahigh UV responsivity of single nonpolar a-axial GaN nanowire with asymmetric piezopotential via piezo-phototronic effect
T2 - Dependence of carrier screening effect on strain
AU - Tsai, Chen Yu
AU - Gupta, Kapil
AU - Wang, Chao Hung
AU - Liu, Chuan Pu
N1 - Funding Information:
This research was supported by the Ministry of Science and Technology of Taiwan (MOST 104-2221-E-006-078-MY3). The authors wish to thank the Center for Micro/Nano Science and Technology, National Cheng Kung University, for providing equipment and technical support.
Publisher Copyright:
© 2017 Elsevier Ltd
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2017/4/1
Y1 - 2017/4/1
N2 - Here, we report on the ultrahigh UV responsivity of 1.3×105 (A/W) on a single nonpolar a-axial GaN nanowire (NW) based metal-semiconductor-metal (M-S-M) UV photodetector (PD), incorporating the piezo-phototronic effect. An exceptional enhancement of 160% from 5×104 to 1.3×105 (A/W) in the UV responsivity when applying a 0.012% tensile strain is achieved. To the best of our knowledge, this is the best performance gained from a single GaN NW PD without employing additional surface treatment. Moreover, an extraordinary phenomenon in the output current is observed showing that the UV responsivity reaches the maximum only at an optimum applied strain and then falls off. This new nonlinear phenomenon is further verified by showing the shift of the maximum UV responsivity toward the higher tensile stress with increasing carrier concentration, through comprehensive analysis on the dependence of the carrier screening effect on both the strain-induced Schottky barrier height (SBH) effect and gating effect, induced by the unique asymmetric piezopotential distribution in a strained a-axial GaN NW. Therefore, this work provides a new design rule for better utilizing piezopotential in coupling with light to achieve the highest performance in optoelectronic devices incorporating piezo-phototronics.
AB - Here, we report on the ultrahigh UV responsivity of 1.3×105 (A/W) on a single nonpolar a-axial GaN nanowire (NW) based metal-semiconductor-metal (M-S-M) UV photodetector (PD), incorporating the piezo-phototronic effect. An exceptional enhancement of 160% from 5×104 to 1.3×105 (A/W) in the UV responsivity when applying a 0.012% tensile strain is achieved. To the best of our knowledge, this is the best performance gained from a single GaN NW PD without employing additional surface treatment. Moreover, an extraordinary phenomenon in the output current is observed showing that the UV responsivity reaches the maximum only at an optimum applied strain and then falls off. This new nonlinear phenomenon is further verified by showing the shift of the maximum UV responsivity toward the higher tensile stress with increasing carrier concentration, through comprehensive analysis on the dependence of the carrier screening effect on both the strain-induced Schottky barrier height (SBH) effect and gating effect, induced by the unique asymmetric piezopotential distribution in a strained a-axial GaN NW. Therefore, this work provides a new design rule for better utilizing piezopotential in coupling with light to achieve the highest performance in optoelectronic devices incorporating piezo-phototronics.
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U2 - 10.1016/j.nanoen.2017.02.052
DO - 10.1016/j.nanoen.2017.02.052
M3 - Article
AN - SCOPUS:85014341387
VL - 34
SP - 367
EP - 374
JO - Nano Energy
JF - Nano Energy
SN - 2211-2855
ER -