Molecule-modulated photoconductivity and gain-amplified selective gas sensing in polar GaN nanowires

Chen, R. S.; Lu, C. Y.; Chen, K. H.; Chen, L. C.
December 2009
Applied Physics Letters;12/7/2009, Vol. 95 Issue 23, p233119
Academic Journal
We report the strong molecular effects on the surface-dominant photoconductivity with high-gain transport in the polar GaN nanowires. Both the transient and steady-state photocurrents are sensitive and selective to the adsorptions of oxygen and hydrogen. The surface band bending of GaN nanowires is proposed to be effectively reduced or enhanced by oxygen or hydrogen, respectively, as a donorlike or acceptorlike surface state. The molecular effect, corroborated with the high-gain photoresponse nature of GaN nanowires is found to amplify the molecule-selective photocurrent signal by near three orders of magnitude higher than its counterpart in dark current. The molecule-tunable photoconductivity, as demonstrated here, would benefit a variety of applications, ranging from the high-gain optoelectronic devices, photoelectric energy transducer, as well as gas and chemical sensors.


Related Articles

  • TiO2 nanoparticles and silicon nanowires hybrid device: Role of interface on electrical, dielectric, and photodetection properties. Rasool, Kamran; Rafiq, M. A.; Ahmad, Mushtaq; Imran, Z.; Hasan, M. M. // Applied Physics Letters;12/17/2012, Vol. 101 Issue 25, p253104 

    We report ∼12, 5, 12, 100, and 70 times enhancement of external quantum efficiency, detectivity, responsivity, AC conductivity, and overall dielectric constant ([variant_greek_epsilon]′), respectively of hybrid silicon nanowires (SiNWs) and titania (TiO2) nanoparticles (NPs) device as...

  • Effects of electrical contacts on the photoconductive gain of nanowire photodetectors. Park, Hongsik; Kim, Jin Ho; Beresford, Roderic; Xu, Jimmy // Applied Physics Letters;10/3/2011, Vol. 99 Issue 14, p143110 

    The mechanism of the photoconductive gains of nanowire (NW) photodetectors has not been clearly explained yet, although it is generally thought to be the result of a long excess carrier lifetime due to a large trap density. Here, we demonstrate that the photoconductive gain of a Bi2S3 NW...

  • Persistent Photoconductivity Studies in Nanostructured ZnO UV Sensors. Hullavarad, Shiva; Hullavarad, Nilima; Look, David; Claflin, Bruce // Nanoscale Research Letters;Dec2009, Vol. 4 Issue 12, p1421 

    The phenomenon of persistent photoconductivity is elusive and has not been addressed to an extent to attract attention both in micro and nanoscale devices due to unavailability of clear material systems and device configurations capable of providing comprehensive information. In this work, we...

  • Photoconductivity in single AlN nanowires by subband gap excitation. Huang, H. M.; Chen, R. S.; Chen, H. Y.; Liu, T. W.; Kuo, C. C.; Chen, C. P.; Hsu, H. C.; Chen, L. C.; Chen, K. H.; Yang, Y. J. // Applied Physics Letters;2/8/2010, Vol. 96 Issue 6, p062104 

    Photoconductivity of individual aluminum nitride (AlN) nanowires has been characterized using different subband gap excitation sources. It is interesting that both positive (under 1.53 and 2.33 eV excitations) and negative (under 3.06 and 3.81 eV excitations) photocurrent responses are observed...

  • Optical modulation of persistent photoconductivity in ZnO nanowires. Yao Wang; Zhaoliang Liao; Guangwei She; Lixuan Mu; Dongmin Chen; Wensheng Shi // Applied Physics Letters;5/16/2011, Vol. 98 Issue 20, p203108 

    In this study, ZnO nanowires (ZNWs)-based optoelectric devices are found to exhibit strong persistent photoconductivity (PPC) effect. An optical modulation on the PPC effect of the ZNWs with 980 nm infrared (IR) laser has been investigated. It was found that the decay time for the PPC can be...

  • W18O49 Nanowires as Ultraviolet Photodetector. Feng Yang; Kai Huang; Shibing Ni; Qi Wang; Deyan He // Nanoscale Research Letters;Feb2010, Vol. 5 Issue 2, p416 

    Photodetectors in a configuration of field effect transistor were fabricated based on individual W18O49 nanowires. Evaluation of electrical transport behavior indicates that the W18O49 nanowires are n-type semiconductors. The photodetectors show high sensitivity, stability and reversibility to...

  • Nanophotonics: Light-emitting indium tin oxide. Horiuchi, Noriaki // Nature Photonics;Jun2011, Vol. 5 Issue 6, p332 

    The article focuses on the conducting material indium tin oxide, its importance on the nanophonotic circuitry as nanowires, and its light-emitting functionality useful for optoelectronic devices.

  • Laying nanowires down with optoelectronic tweezers. P. F. S. // Physics Today;Jul2007, Vol. 60 Issue 7, p29 

    The article focuses on research examining methods of laying down nanowires. It states that standard optical tweezers are used to manipulate individual particles by trapping the particle in a focused laser's strong field gradient. The article mentions a new method that uses optoelectronic...

  • Depletion-Mode Photoconductivity Study of Deep Levels in GaN Nanowires. Armstrong, A.; Wang, G. T.; Talin, A. A. // Journal of Electronic Materials;Apr2009, Vol. 38 Issue 4, p484 

    The steady-state photoconductivity (PC) response of deep level defects to sub-bandgap illumination was studied in GaN nanowires (NWs) grown by metalorganic chemical vapor deposition. Photoemission from defects residing in the NW surface depletion region alters the depletion width, and the PC...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics