Recombination at GaAs surfaces and GaAs/AlGaAs interfaces probed by <i>in</i> <i>situ</i> photoluminescence

Sandroff, C. J.; Turco-Sandroff, F. S.; Florez, L. T.; Harbison, J. P.

doi:10.1063/1.349210

Cited by 19 publications

(4 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In situ PL has also been used to probe the passivation of GaAs with heteroepitaxial AlGaAs monolayer by monolayer. 33 Conducting a similar study outside the growth chamber would have required a long sequence of separate growth runs, where run-to-run scatter in growth conditions could be problematic. Timoshenko et al have extended the in situ PL technique to evaluate electrochemical treatments of indirect semiconductor surfaces, where pulsed excitation is required to obtain a sufficient PL signal.…”

Section: Photoluminescence Intensitymentioning

confidence: 99%

Photoluminescence in Analysis of Surfaces and Interfaces

Gfroerer

2000

Encyclopedia of Analytical Chemistry

128

100

View full text Add to dashboard Cite

Photoluminescence (PL) is the spontaneous emission of light from a material under optical excitation. The excitation energy and intensity are chosen to probe different regions and excitation concentrations in the sample. PL investigations can be used to characterize a variety of material parameters. PL spectroscopy provides electrical (as opposed to mechanical) characterization, and it is a selective and extremely sensitive probe of discrete electronic states. Features of the emission spectrum can be used to identify surface, interface, and impurity levels and to gauge alloy disorder and interface roughness. The intensity of the PL signal provides information on the quality of surfaces and interfaces. Under pulsed excitation, the transient PLintensity yields the lifetime of nonequilibrium interface and bulk states. Variation of the PL intensity under an applied bias can be used to map the electric field at the surface of a sample. In addition, thermally activated processes cause changes in PL intensity with temperature. PL analysis is nondestructive. Indeed, the technique requires very little sample manipulation or environmental control. Because the sample is excited optically, electrical contacts and junctions are unnecessary and high‐resistivity materials pose no practical difficulty. In addition, time‐resolved PL can be very fast, making it useful for characterizing the most rapid processes in a material. The fundamental limitation of PL analysis is its reliance on radiative events. Materials with poor radiative efficiency, such as low‐quality indirect bandgap semiconductors, are difficult to study via ordinary PL. Similarly, identification of impurity and defect states depends on their optical activity. Although PL is a very sensitive probe of radiative levels, one must rely on secondary evidence to study states that couple weakly with light.

show abstract

Section: Photoluminescence Intensitymentioning

confidence: 99%

Photoluminescence in Analysis of Surfaces and Interfaces

Gfroerer

2000

Encyclopedia of Analytical Chemistry

128

100

View full text Add to dashboard Cite

show abstract

“…[1][2][3][4][5] Reduction in the number density of surface impurities responsible for midgap states results in reduced band bending and/or a reduction in the effective surface recombination velocity, thereby increasing the net PL efficiency ͑i.e., quantum yield͒ of the surface treated sample. Photoexcitation alone can also have these effects on GaAs, with a reduction in band bending resulting from charge separation in the depletion layer following photoexcitation, and a reduction in the surface trap density resulting from midgap state filling on a timescale that is short compared with the actual recombination event.…”

Section: Department Of Chemistry University Of Missouri-columbia Comentioning

confidence: 99%

Excitation power dependence of photoluminescence enhancement from passivated GaAs

Liu

Kauffman

1995

Applied Physics Letters

View full text Add to dashboard Cite

Photoluminescence (PL) efficiency plots versus laser excitation power are presented for bare and Na2S treated n-GaAs. The plots demonstrate an increase in PL quantum yield with increasing excitation power density for both samples. The PL enhancement observed in the Na2S treated sample is presented and is shown to depend strongly on excitation power density. Application of the deadlayer model to the analysis of low power PL efficiency from bare GaAs indicates that surface electron-hole recombination is significantly slower than surface minority carrier trapping.

show abstract

“…The chemical passivation of 111-V compound semiconduo tors, and especially GaAs, i s receiving increasing attention. For this purpose the semiconductor surface is exposed to inorganic chemicals such as (NH,),S, Na,S.9H20 and H,S for sulphur passivation [l-41 and Na,Se and K,Se for selenium passivation [5-71. Reduc-tic= in sc&ce State dezsity rl 5, 7; 2nd periFAeter recombination current [2], an increase in photoluminescence [3,6] and gain of heterostructure bipolar transistor [4] have been observed. The purpose of this study is to explore the effect of selenium passivation of GaAs on the properties of metal-insulator-semiconductor (MIS) Schottky diodes.…”

Section: Introductionmentioning

confidence: 92%

Electrical characteristics of selenium-treated GaAs MIS Schottky diodes

Eftekhari

1993

Semicond. Sci. Technol.

View full text Add to dashboard Cite

We have investigated the effect of selenium treatment of GaAs on the metal-insulator-semiconductor (MIS) Schottky diode characteristics. The resuits show that the surface-state density and trap density at the interface decrease. This resu!'; in decrease in the harrier height and retierse cwe.!. The treated diodes showed little aging effect. These observations can be explained using t h e formation of arsenic-selenium and selenium-selenium bonds at the surface and in the thin layer next to the surface within the GaAs.

show abstract

Recombination at GaAs surfaces and GaAs/AlGaAs interfaces probed by in situ photoluminescence

Cited by 19 publications

References 19 publications

Photoluminescence in Analysis of Surfaces and Interfaces

Photoluminescence in Analysis of Surfaces and Interfaces

Excitation power dependence of photoluminescence enhancement from passivated GaAs

Electrical characteristics of selenium-treated GaAs MIS Schottky diodes

Contact Info

Product

Resources

About