TY - JOUR
T1 - Structural engineering of nano-grain boundaries for low-voltage UV-Photodetectors with gigantic photo- to dark-current ratios
AU - Nasiri, Noushin
AU - Bo, Renheng
AU - Chen, Hongjun
AU - White, Thomas P.
AU - Fu, Lan
AU - Tricoli, Antonio
PY - 2016/11
Y1 - 2016/11
N2 - Ultraporous networks of ZnO nanoparticles (UNN) have recently been proposed as a highly performing morphology for portable ultraviolet light photodetectors. Here, it is shown that structural engineering of the nanoparticle grain boundaries can drastically enhance the performance of UNN photodetectors leading to gigantic photo to dark current ratios with operation voltages below 1 V. Ultraporous nanoparticle layers are fabricated by scalable low-temperature deposition of flame-made ZnO aerosols resulting in highly transparent layers with more than 95% visible light transmittance and 80% UV-light absorption. Optimal thermally induced necking of the ZnO nanoparticles increased the photo- to dark-current ratio, at a low light density of 86 μW cm−2, from 1.4 × 104 to 9.3 × 106, the highest so far reported. This is attributed to the optimal interplay of surface depletion and carrier conduction resulting in the formation of an open-neck grain boundary morphology. These findings provide a robust set of guiding principles for the design and fabrication of nanoparticle-based optoelectronic devices.
AB - Ultraporous networks of ZnO nanoparticles (UNN) have recently been proposed as a highly performing morphology for portable ultraviolet light photodetectors. Here, it is shown that structural engineering of the nanoparticle grain boundaries can drastically enhance the performance of UNN photodetectors leading to gigantic photo to dark current ratios with operation voltages below 1 V. Ultraporous nanoparticle layers are fabricated by scalable low-temperature deposition of flame-made ZnO aerosols resulting in highly transparent layers with more than 95% visible light transmittance and 80% UV-light absorption. Optimal thermally induced necking of the ZnO nanoparticles increased the photo- to dark-current ratio, at a low light density of 86 μW cm−2, from 1.4 × 104 to 9.3 × 106, the highest so far reported. This is attributed to the optimal interplay of surface depletion and carrier conduction resulting in the formation of an open-neck grain boundary morphology. These findings provide a robust set of guiding principles for the design and fabrication of nanoparticle-based optoelectronic devices.
UR - http://www.scopus.com/inward/record.url?scp=84979763395&partnerID=8YFLogxK
UR - http://purl.org/au-research/grants/arc/DP150101939
UR - http://purl.org/au-research/grants/arc/DE160100569
U2 - 10.1002/adom.201600273
DO - 10.1002/adom.201600273
M3 - Article
AN - SCOPUS:84979763395
SN - 2195-1071
VL - 4
SP - 1787
EP - 1795
JO - Advanced Optical Materials
JF - Advanced Optical Materials
IS - 11
ER -