Some Characteristics of GaAs–Ge Epitaxy

Epitaxy of GaAs by the Close‐Spaced Vapor Transport Technique

“…They also reported that the ratio n3oo/n77 decreased with the donor doping, becoming unity for a donor concentration of about 3 • 10 '7 cm -3. perimental and calculated values, one can conclude that the hypotheses used in the CSVT model can be accepted. It is to be noticed that S~ GaAs = 11.2 or 11.7 cal mo1-1 K -1 and All~ GaAs = -19.5 kcal mol-', used in the present model to adjust the experimental growth rate data, are very close to the thermodynamic values found by Abbasov (49) using the method of electromotive forces in the following cell (-)Ga(1) I (KCI, NaCI) + GaCI3 I (GaAs + As) + [25] These values were: S~ GaAs = 11.4 -+ 1.8 cal mol -I K -' and AH~ GaAs = -19.4 +-1.8 kcal tool-'.…”

“…GaAs, GaP, and GaAsxPl_x films have also been grown by CSVT in the early days of this technique (22)(23)(24)(25)(26)(27)(28) and then again quite recently (29)(30)(31). These studies have shown the important role of water vapor usually used as transporting reagent, although I2 or ZnC12 have also been proposed for the same purpose.…”

“…The growth Characteristics of the III-V semiconductor films have often been investigated, but their transport properties have only been measured in a few cases and under rather different growth conditions. For instance, Schulze reported n-type GaAs films with a charge carrier density, n = 1.4 • 10 TM cm -3, and with a low Hall mobility, ~ = 290 cm 2 V-Is -1, in the case of GaAs/Ge layers using Iz as transport reagent (25). Degenerate p-type GaAs (n = 5 • 10 TM cm -3) was obtained by CSVT with ZnC12 as transport reagent (27).…”

Infrared Photocathode Research

“…From Isawa ( and from Schulze (9) we determine that the As surface concentration is approximately 1 x 10 19 . This is confirmed by our own measurements on 6 x 10 18 cm" 3 and 2 x 10 cm Ge substrates.…”

“…9 5-Cs 2 0 in the spectral range from 0,4 to l. Iß. The highest quantum yields yet reported were observed in this emitter.…”