Evidence for negatively charged DX-center in Si-doped AlGaAs from persistent photoconductivity measurements

ABSTRACTPressure dependent Deep Level Transient Spectroscopy (DLTS) experiments are used to measure the properties of the deep donors (DX-centers) responsible for the persistent photoconductivity effect in Si-doped AlGaAs. The sample dependence of the DLTS spectra shows evidence for a defect complex involved in the DX-center.

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New type of persistent photoconductivity related to DX-center: the study of interband PPC in Si-doped AlGaAs

Physica B Condensed Matter ◽

10.1016/s0921-4526(99)00651-1 ◽

1999 ◽

Vol 273-274 ◽

pp. 792-795 ◽

Cited By ~ 4

Author(s):

R Piotrzkowski ◽

E Litwin-Staszewska ◽

F Bosc ◽

J Sicart ◽

J.L Robert

Keyword(s):

Persistent Photoconductivity ◽

New Type ◽

Si Doped ◽

Dx Center

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Doping Study of Se into AlGaAs Layers Grown by MBE, and their Application to HEMT Structures

MRS Proceedings ◽

10.1557/proc-144-239 ◽

1988 ◽

Vol 144 ◽

Cited By ~ 2

Author(s):

T. Maed ◽

T. Ishikawa ◽

K. Kondo

Keyword(s):

Molecular Beam ◽

Electron Gas ◽

Dimensional Electron ◽

Two Dimensional Electron Gas ◽

Si Doping ◽

Se Doping ◽

Si Doped ◽

Dx Center ◽

Dimensional Electron Gas ◽

Dopant Source

ABSTRACTWe studied doping Se into AlGaAs layers using PbSe as a dopant source for molecular beam epitaxy (MBE). Good controllability and abruptness equivalent to that of Si-doping were obtained. Se-doping was successfully applied to HEMT structures with reduced DX center concentrations. The two dimensional electron gas (2DEG) characteristics of these structures were comparable to those of Si-doped structures.

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STABILITY OF SI-DOPED AlGaAs/GaAs MODFET STRUCTURES DURING CONVENTIONAL FURNACE AND RAPID OPTICAL ANNEALING.

MRS Proceedings ◽

10.1557/proc-56-301 ◽

1985 ◽

Vol 56 ◽

Cited By ~ 1

Author(s):

J. K. ABROKWAH ◽

H. HIBBS ◽

R. R. DANIELS ◽

P. JOSLYN

Keyword(s):

High Performance ◽

The Self ◽

Superlattice Structure ◽

Annealing Conditions ◽

Conventional Furnace ◽

Algaas Layer ◽

Si Doped ◽

Dx Center ◽

Superlattice Structures ◽

The Stability

AbstractThe use of an AlGaAs/n-GaAs superlattice in place of the n-AlGaAs layer in MODFET devices reduces the light and temperature sensitivity of the threshold voltage. This paper considers the stability of Si doped superlattices under annealing conditions required for activation of the implant in the self-aligned gate MODFET fabrication process. Rapid optical annealing does not significantly degrade the superlattice structure. The DX center concentration in the superlattice structures is a factor of 30 less than measured in conventional MODFET structures. High performance MOOFET devices have been fabricated using the self-aligned gate process with rapid optical annealing.

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Persistent photoconductivity in AlGaN films Grown by mocvd

MRS Proceedings ◽

10.1557/proc-512-537 ◽

1998 ◽

Vol 512 ◽

Cited By ~ 2

Author(s):

A. Y. Polyakov ◽

N. B. Smirnov ◽

A. V. Govorkov ◽

J. M. Redwing

Keyword(s):

Activation Energy ◽

Light Intensity ◽

High Resistivity ◽

Persistent Photoconductivity ◽

Quasi Fermi Level ◽

Decay Times ◽

Long Time ◽

Light Excitation ◽

Si Doped ◽

Kinetics Of

ABSTRACTPhotocurrent transients due to illumination by above-bandgap and subbandgap light were studied for Si doped and undoped films of AlGaN grown by MOCVD on sapphire and having compositions ranging from 0% to 60% of Al. It is shown that in Si doped layers the decay of photoconductivity takes extremely long time (hundreds and thousands seconds, depending on temperature, composition and illumination conditions). Both the kinetics of rise and fall of photoconductivity are best described by stretched exponents. The characteristic decay times are virtually temperature independent for temperatures below 270–290K and have activation energy of 0.14–0.26 eV (depending on composition) for higher temperatures. The decay times become longer with decreased light intensity and increase when above-bandgap light excitation is replaced by subbandgap light excitation (the photocurrent values from which the decay starts being equivalent). The results cannot be quantitatively explained by the effects of changing of the quasi-Fermi level position well known for DX-centers in AlGaAs. No persistent photoconductivity could be observed in high resistivity undoped AlGaN films with 5%, 15% and 25% of Al.

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A Photocapture Test of DX-Center Models

MRS Proceedings ◽

10.1557/proc-163-773 ◽

1989 ◽

Vol 163 ◽

Cited By ~ 1

Author(s):

Harold P. Hjalmarson ◽

S. R. Kurtz ◽

T. M. Brennan

Keyword(s):

Conduction Band ◽

Cross Section ◽

Threshold Energy ◽

Photoionization Cross Section ◽

Persistent Photoconductivity ◽

Dx Centers ◽

Null Result ◽

Dx Center

AbstractThe DX-center model is widely used to explain data for the persistent photoconductivity (PPC) effect. An analysis of the DX-center model suggests a new experiment to test its correctness. In this experiment, photons near the threshold energy of the photoionization cross-section for the DX-center induce transitions from the partially occupied conduction band to empty DX-centers. This mechanism, which we call photocapture, competes with the usual photoionization which empties the DX-centers. The photocapture cross-section is estimated and an experimental attempt is made to detect photocapture. The significance of the null result is discussed.

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Growth Condition Independence Observed for DX Center in Si-doped AlGaAs Grown by Molecular Beam Epitaxy

Japanese Journal of Applied Physics ◽

10.1143/jjap.24.l883 ◽

1985 ◽

Vol 24 (Part 2, No. 11) ◽

pp. L883-L884 ◽

Cited By ~ 8

Author(s):

Yasuo Ashizawa ◽

Miyoko Oku Watanabe

Keyword(s):

Molecular Beam Epitaxy ◽

Growth Condition ◽

Molecular Beam ◽

Si Doped ◽

Dx Center

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DX‐center‐like traps and persistent photoconductivity in Te‐doped AlxGa1−xSb on GaSb

Journal of Applied Physics ◽

10.1063/1.341740 ◽

1988 ◽

Vol 64 (4) ◽

pp. 1897-1901 ◽

Cited By ~ 29

Author(s):

Yu Zhu ◽

Yoshikazu Takeda ◽

Akio Sasaki

Keyword(s):

Persistent Photoconductivity ◽

Dx Center

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Chemical trends of deep levels in van der Waals semiconductors

Nature Communications ◽

10.1038/s41467-020-19247-1 ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Penghong Ci ◽

Xuezeng Tian ◽

Jun Kang ◽

Anthony Salazar ◽

Kazutaka Eriguchi ◽

...

Keyword(s):

Deep Level ◽

Energy Levels ◽

Van Der Waals ◽

Deep Levels ◽

Persistent Photoconductivity ◽

Sulfur Vacancy ◽

Native Defects ◽

Crystal Imperfections ◽

Dx Center ◽

Chemical Trends

AbstractProperties of semiconductors are largely defined by crystal imperfections including native defects. Van der Waals (vdW) semiconductors, a newly emerged class of materials, are no exception: defects exist even in the purest materials and strongly affect their electrical, optical, magnetic, catalytic and sensing properties. However, unlike conventional semiconductors where energy levels of defects are well documented, they are experimentally unknown in even the best studied vdW semiconductors, impeding the understanding and utilization of these materials. Here, we directly evaluate deep levels and their chemical trends in the bandgap of MoS2, WS2 and their alloys by transient spectroscopic study. One of the deep levels is found to follow the conduction band minimum of each host, attributed to the native sulfur vacancy. A switchable, DX center - like deep level has also been identified, whose energy lines up instead on a fixed level across different hosts, explaining a persistent photoconductivity above 400 K.

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