Unpinned behavior of the surface Fermi level of GaN detected by photoreflectance spectroscopy

被引：30

作者：

Behn, U

Thamm, A

Brandt, O

Grahn, HT

机构：

[1] Paul Drude Inst Festkorperelekt, D-10117 Berlin, Germany

[2] Fachsch Schmalkalden, D-98574 Schmalkalden, Germany

来源：

JOURNAL OF APPLIED PHYSICS | 2000年 / 87卷 / 09期

关键词：

D O I：

10.1063/1.373071

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

The photoreflectance signal from GaN films is sensitive to the ambient medium. A large decrease in the photoreflectance amplitude is observed, when the ambient medium is changed from air to vacuum. This effect is attributed to ultraviolet-light-induced desorption of oxygen from the sample surface leading to a reduction of the surface barrier height. The effect is absent, when a thin Ti layer is deposited on top of the GaN film. A simple model is used to demonstrate that the surface photovoltage can be strongly reduced with a decrease of the surface barrier height. (C) 2000 American Institute of Physics. [S0021-8979(00)05009-X].

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页码：4315 / 4318

页数：4

相关论文

共 19 条

[1] DOMINATION OF ADATOM-INDUCED OVER DEFECT-INDUCED SURFACE-STATES ON P-TYPE GAAS(CS,O) AT ROOM-TEMPERATURE [J].

ALPEROVICH, VL ;

PAULISH, AG ;

TEREKHOV, AS .

PHYSICAL REVIEW B, 1994, 50 (08) :5480-5483

[2] THEORETICAL AND EXPERIMENTAL RESULTS FOR P-TYPE GAAS ELECTROLYTE ELECTROREFLECTANCE [J].

BATCHELOR, RA ;

BROWN, AC ;

HAMNETT, A .

PHYSICAL REVIEW B, 1990, 41 (03) :1401-1412

[3] WANNIER EXCITON IN AN ELECTRIC FIELD .2. ELECTROABSORPTION IN DIRECT-BAND-GAP SOLIDS [J].

BLOSSEY, DF .

PHYSICAL REVIEW B, 1971, 3 (04) :1382-&

[4]

Bube RH., 1960, Photoconductivity of Solids

[5] Analysis of Fermi level pinning and surface state distribution in InAlAs heterostructures [J].

Chou, WY ;

Chang, GS ;

Hwang, WC ;

Hwang, JS .

JOURNAL OF APPLIED PHYSICS, 1998, 83 (07) :3690-3695

[6] DYNAMICS OF ELECTRIC-FIELD SCREENING IN A BULK GAAS MODULATOR [J].

HEESEL, H ;

HUNSCHE, S ;

MIKKELSEN, H ;

DEKORSY, T ;

LEO, K ;

KURZ, H .

PHYSICAL REVIEW B, 1993, 47 (23) :16000-16003

[7] Built-in electric field and surface Fermi level in InP surface-intrinsic n(+) structures by modulation spectroscopy [J].

Hwang, JS ;

Chou, WY ;

Hung, MC ;

Wang, JS ;

Lin, HH .

JOURNAL OF APPLIED PHYSICS, 1997, 82 (08) :3888-3890

[8] PHOTOREFLECTANCE CHARACTERIZATION OF SURFACE FERMI LEVEL IN AS-GROWN GAAS(100) [J].

KANATA, T ;

MATSUNAGA, M ;

TAKAKURA, H ;

HAMAKAWA, Y ;

NISHINO, T .

JOURNAL OF APPLIED PHYSICS, 1990, 68 (10) :5309-5313

[9] Photoreflectance of low-temperature-grown GaAs on Si-delta-doped GaAs [J].

Lee, WC ;

Hsu, TM ;

Chyi, JI .

APPLIED SURFACE SCIENCE, 1997, 113 :515-518

[10] Photoreflectance spectroscopy investigation of two-dimensional cesium metallic clusters on GaAs(100) [J].

Paget, D ;

Kierren, B ;

Houdre, R .

JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS, 1998, 16 (04) :2350-2359