PMID- 30875973
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20201001
IS  - 2079-4991 (Print)
IS  - 2079-4991 (Electronic)
IS  - 2079-4991 (Linking)
VI  - 9
IP  - 3
DP  - 2019 Mar 15
TI  - High-Performance Ultraviolet Light Detection Using Nano-Scale-Fin Isolation 
      AlGaN/GaN Heterostructures with ZnO Nanorods.
LID - 10.3390/nano9030440 [doi]
LID - 440
AB  - Owing to their intrinsic wide bandgap properties ZnO and GaN materials are widely 
      used for fabricating passive-type visible-blind ultraviolet (UV) photodetectors 
      (PDs). However, most of these PDs have a very low spectral responsivity R, which 
      is not sufficient for detecting very low-level UV signals. We demonstrate an 
      active type UV PD with a ZnO nanorod (NR) structure for the floating gate of 
      AlGaN/GaN high electron mobility transistor (HEMT), where the AlGaN/GaN epitaxial 
      layers are isolated by the nano-scale fins (NFIs) of two different fin widths (70 
      and 80 nm). In the dark condition, oxygen adsorbed at the surface of the ZnO NRs 
      generates negative gate potential. Upon UV light illumination, the negative 
      charge on the ZnO NRs is reduced due to desorption of oxygen, and this reversible 
      process controls the source-drain carrier transport property of HEMT based PDs. 
      The NFI PDs of a 70 nm fin width show the highest R of a ~3.2 x 10(7) A/W at 340 nm 
      wavelength among the solid-state UV PDs reported to date. We also compare the 
      performances of NFI PDs with those of conventional mesa isolation (MI, 40 x 100 
      microm(2)). NFI devices show ~100 times enhanced R and on-off current ratio than those 
      of MI devices. Due to the volume effect of the small active region, a much faster 
      response speed (rise-up and fall-off times of 0.21 and 1.05 s) is also obtained 
      from the NFI PDs with a 70 nm fin width upon the UV on-off transient.
FAU - Khan, Fasihullah
AU  - Khan F
AUID- ORCID: 0000-0001-7566-8740
AD  - Division of Electronics and Electrical Engineering, Dongguk University, Seoul 
      100-715, Korea. fasihullah.khan@dongguk.edu.
FAU - Khan, Waqar
AU  - Khan W
AUID- ORCID: 0000-0003-0123-6456
AD  - Division of Electronics and Electrical Engineering, Dongguk University, Seoul 
      100-715, Korea. waqarkyz@gmail.com.
FAU - Kim, Sam-Dong
AU  - Kim SD
AD  - Division of Electronics and Electrical Engineering, Dongguk University, Seoul 
      100-715, Korea. samdong@dongguk.edu.
LA  - eng
GR  - 2016006533/National Research Foundation of Korea/
GR  - 2009-0082580/National Research Foundation of Korea/
PT  - Journal Article
DEP - 20190315
PL  - Switzerland
TA  - Nanomaterials (Basel)
JT  - Nanomaterials (Basel, Switzerland)
JID - 101610216
PMC - PMC6474106
OTO - NOTNLM
OT  - ZnO nanorods
OT  - high-responsivity
OT  - nano-scale fin isolation
OT  - two-dimensional electron gas
OT  - ultraviolet photodetectors
OT  - visible-blind
OT  - wide-band gap semiconductors
COIS- The authors declare no conflicts of interest.
EDAT- 2019/03/17 06:00
MHDA- 2019/03/17 06:01
PMCR- 2019/03/15
CRDT- 2019/03/17 06:00
PHST- 2019/02/24 00:00 [received]
PHST- 2019/03/06 00:00 [revised]
PHST- 2019/03/08 00:00 [accepted]
PHST- 2019/03/17 06:00 [entrez]
PHST- 2019/03/17 06:00 [pubmed]
PHST- 2019/03/17 06:01 [medline]
PHST- 2019/03/15 00:00 [pmc-release]
AID - nano9030440 [pii]
AID - nanomaterials-09-00440 [pii]
AID - 10.3390/nano9030440 [doi]
PST - epublish
SO  - Nanomaterials (Basel). 2019 Mar 15;9(3):440. doi: 10.3390/nano9030440.