Deep levels in GaN studied by extrinsic photoconductivity measurement

Conference · Wed Dec 31 04:00:00 EST 1997

OSTI ID:581107

Zhang, R ^[1]; Huang, Z ^[2]; Guo, B; Chen, J C; Yan, L ^[1]; Zheng, Y ^[3]; Kuech, T F ^[4]

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1. Univ. of Maryland Baltimore County, MD (United States)
2. NASA Goddard Space Flight Center, Greenbelt, MD (United States)
3. Nanjing Univ. (China). Dept. of Physics
4. Univ. of Wisconsin, Madison, WI (United States)

Modulation Extrinsic photoconductivity spectra between 1.44 eV and 1.75 eV of unintentionally n-doped high resistance GaN film grown by MOCVD are measured at room temperature by using wavelength adjustable Ti:Sapphire laser. The authors find that there are two major deep levels in the GaN material in the used photon energy range. The relaxation time of excess carriers controlled by those levels are in the order of 10{sup {minus}4}sec. The concentration of localized states are determined as 1.8 {times} 10{sup 8}cm{sup {minus}3} and 2.5 {times} 10{sup 9}cm{sup {minus}3}, respectively. A physical model is developed to explain the results and process the data. Using a new method they have determined the optical absorption cross section of deep levels are 1.5 {times} 10{sup {minus}17}cm{sup 2} and 2.7 {times} 10{sup {minus}18}cm{sup 2}, respectively.

• OSTI ID: 581107
• Report Number(s): CONF-961202--; ISBN 1-55899-353-3
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHARGE CARRIERS
CHEMICAL VAPOR DEPOSITION
DOPED MATERIALS
ELECTRICAL PROPERTIES
GALLIUM NITRIDES
PHOTOCONDUCTIVITY