Experimental data indicate that optimum doping exists. Measured quantum yield curves indicate optimum overall response is obtained in GaAs emitters with doping in high 10 to the 18th power per cu cm range. Doping for optimum response is not necessarily in this range

Sonnenberg, H.

English

NASA Technical Reports Server

September 1971
	 Brief 71-10357 
•	 NASA TECH BRIEF 
Marshall Space Flight Center
	
_4V 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage 
commercial application. Tech Briefs are available on a subscription basis from the National Technical Information 
Service, Springfield, Virginia 22151. Requests for individual copies or questions relating to the. Tech Brief program may 
be directed to the Technology Utilization Office, NASA, Code KT, Washington, D.C. 20546.
IIIIIM 
Optimum Doping Achieves High Quantum Yields in GaAs Photoemitters 
.
The doping range resulting in optimum photoemis-
sion from GaAs-Cs20 has been investigated more 
extensively. Previously, investigations of photo-
emission from p-type GaAs-Cs 2 0 were confined 
primarily to materials with an acceptor concentra-
tion in the range of 1x10 19 to 5x10 19 atoms per 
cm -3. Recently, however, it was shown that, for low 
work-function surfaces of Cs 20, quantum yields 
as high as those obtained on 4x10 19 cm-3 Zn-doped 
GaAs-Cs-)O could be achieved in 2x10 17
 cm-3 
GaAs. The photoemission from ultra-high vacuum 
cleaved GaAs-Cs20 was measured in the acceptor 
density range between 3.3x10 16
 and 4.6x10 19 cm-3. 
The data obtained from the experimental investiga-
tions clearly indicate that an optimum doping range 
exists. Measured, quantum yield curves indicate that 
an optimum overall response is obtained in GaAs 
emitters with doping in the high 10 18
 cm-73 range. 
However, the doping for optimum response at 
a given wavelength is not necessarily in this range, 
as indicated in the figure where the quantum yield 
as a function of acceptor concentration is plotted, 
with wavelength as a parameter. For example, at 
9250 A, the higher the doping level, the better the
response. At 9000 A, peak response is obtained with 
GaAs doped in the low 10 19 CM-73 range. At 8500 A, 
the peak response is obtained in the 1018 cm -3 range. 
As a general guideline, for overall optimum photo-
response, p-GaAs material with the highest electron 
mobility in the doping range between 6x1018 
and lx 1019 cm-3 should be selected. 
Note: 
Requests for further information may be directed 
to:
Technology Utilization Officer 
Code A&TS-TU 
Marshall Space Flight Center 
Huntsville, Alabama 35812 
Reference: TSP71-10357 
Patent status: 
No patent action is contemplated by NASA. 
Source: H. Sonnenberg of

Sylvania Electronic Systems

under contract to
Marshall Space Flight Center

(M FS-20962) 
erlItlil red oe 
This documetct was prepared under the sponsorship of the National	 Government assumes any liability resulting from the use of the 
Aeronautics and Space Administration. Neither the United States 	 information contained in this document, or warrants that such use 
Government nor any person acting on behalf of the United States 	 will be free from privately owned.rights.
https://ntrs.nasa.gov/search.jsp?R=19710000355 2020-03-17T02:29:32+00:00Z
4500A 
-
8500 A 
7T72i 
•
A'
100 
10 
0.01 
n• mi
S 
S 
C 0 
4-. C 
-c 
U 
C 
S...-(I) 
C 
0 
4-. 
C) 
Ui 
-c 
a, 
>-
E 
4-' 
C 
a, 
a 
4-. 
C 
a) 
C)
1.0 
0.1 
o16	 1017	 10 18	 10 19	 1020 
Zn Acceptor Concentration (cm -3) 
Optimum Photoresponse of GaAs—Cs2O as a Function of 
Doping, with Wavelength as Parameter. 
Brief 7l-10357	 Category 03	 0 


Optimum doping achieves high quantum yields in GaAs photoemitters

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server