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| 21. |
Ga0.47In0.53As/InP superlattices grown by chemical beam epitaxy: Absorption, photoluminescence excitation, and photocurrent spectroscopies |
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Applied Physics Letters,
Volume 50,
Issue 9,
1987,
Page 540-542
W. T. Tsang,
E. F. Schubert,
S. N. G. Chu,
K. Tai,
R. Sauer,
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摘要:
Superlattices of Ga0.47In0.53As/InP grown by chemical beam epitaxy (CBE) were studied in detail by transmission electron microscopy, absorption, photoluminescence (PL), photoluminescence excitation (PLE), and photocurrent (PC) spectroscopies. Results from all these characterization techniques independently confirmed the superior qualities of the CBE‐grown Ga0.47In0.53As/InP superlattices over previously reported results. Photoluminescence linewidths were close to those obtained from CBE‐grown single quantum wells. All of the observed excitonic absorption peaks in absorption, PLE, and PC spectra were well resolved and clearly assigned including the forbiddenE13htransition for the first time. In fact, these excitonic structures were still observed in the PC spectra at temperatures as high as 102 °C.
ISSN:0003-6951
DOI:10.1063/1.98153
出版商:AIP
年代:1987
数据来源: AIP
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| 22. |
Upper critical fields and high superconducting transition temperatures of La1.85Sr0.15CuO4and La1.85Ba0.15CuO4 |
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Applied Physics Letters,
Volume 50,
Issue 9,
1987,
Page 543-544
D. W. Capone,
D. G. Hinks,
J. D. Jorgensen,
K. Zhang,
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PDF (218KB)
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摘要:
The superconducting transition temperatureTcof La1.85Sr0.15CuO4is measured to be 34.7 K (midpoint) with a transition width (10–90%) of 2.6 K. The critical field slope atTcis 2.13 T/K. Using the Werthamer, Helfand, and Hohenberg expression in the dirty limit we estimate the upper critical fieldHc2(0) to be at least 50 T for this system. The measured transition width broadens initially with increasing field to 4 K, then saturates at this value for fields above 2 T. The critical field slope for the lowerTcmaterial La1.85Ba0.15CuO4is measured to be 1.78 T/K, which yields anHc2(0) of at least 36 T.
ISSN:0003-6951
DOI:10.1063/1.98154
出版商:AIP
年代:1987
数据来源: AIP
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| 23. |
Electric field distribution of electron emitter surfaces |
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Applied Physics Letters,
Volume 50,
Issue 9,
1987,
Page 545-546
M. Tagawa,
S. Takenobu,
N. Ohmae,
M. Umeno,
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PDF (199KB)
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摘要:
The electric field distribution of a tungsten field emitter surface and a LaB6thermionic emitter surface has been studied. The computer simulation of electric field distribution on the emitter surface was carried out with a charge simulation method. The electric field distribution of the LaB6thermionic emitter was experimentally evaluated by the Schottky plot. Two independent equations are necessary for obtaining local electric field and work function; the Fowler–Nordheim equation and the equation of total energy distribution of emitted electron being used to evaluate the electric field distribution of the tungsten field emitter. The experimental results agreed with the computer simulation.
ISSN:0003-6951
DOI:10.1063/1.98155
出版商:AIP
年代:1987
数据来源: AIP
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