GAP PROPERTIES OF ALNGA8-NAS8 ORDERED COMPOUNDS

被引:20
作者
KOILLER, B
OSORIO, R
FALICOV, LM
机构
[1] UNIV BRASILIA,DEPT FIS,BR-70910 BRASILIA,DF,BRAZIL
[2] UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720
[3] UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV MAT & CHEM SCI,BERKELEY,CA 94720
来源
PHYSICAL REVIEW B | 1991年 / 43卷 / 05期
关键词
D O I
10.1103/PhysRevB.43.4170
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
The small-crystal approach with a 16-site basic cluster is used to determine the electronic structure of 16 inequivalent ordered structures of Al(n)Ga(8-n)As8 compounds. The energy gaps and oscillator strengths for the main gap transitions are calculated, and different results are obtained for different structures of the same composition n, which illustrates the role of compositional ordering in the electronic properties of alloys. Average values of these quantities are used as an attempt to describe Al(x)Ga(1-x)As alloys. Important features of our results are (a) a positive curvature in the averaged gap versus x dependence for small x and (b) a smooth featureless decrease of the averaged oscillator strength with x. This last feature implies that the direct-indirect gap crossover in the alloy system cannot be genuinely obtained by any sort of averaging among Al(n)Ga(8-n)As8 ordered compounds.
引用
收藏
页码:4170 / 4173
页数:4
相关论文
共 26 条
[11]   ALXGA1-XAS BAND-EDGE DEPENDENCE ON ALLOY COMPOSITION [J].
FU, Y ;
CHAO, KA ;
OSORIO, R .
PHYSICAL REVIEW B, 1989, 40 (09) :6417-6419
[12]   TIGHT-BINDING STUDIES OF GA1-XALXAS [J].
HASBUN, JE ;
SINGH, VA ;
ROTH, LM .
PHYSICAL REVIEW B, 1987, 35 (06) :2988-2990
[13]   NEW MODEL OF DEEP DONOR CENTRES IN AlxGa1 - xAs. [J].
Henning, J.C.M. ;
Ansems, J.P.M. .
Semiconductor Science and Technology, 1987, 2 (01) :1-13
[14]   COMMUTATIVITY AND TRANSITIVITY OF GAAS-ALAS-GE(100) BAND OFFSETS [J].
KATNANI, AD ;
BAUER, RS .
PHYSICAL REVIEW B, 1986, 33 (02) :1106-1109
[15]  
KOILLER B, 1990, PHYS REV B, V42, P3194, DOI 10.1103/PhysRevB.42.3194.2
[16]   SMALL-CRYSTAL APPROACH TO ORDERED SEMICONDUCTOR COMPOUNDS [J].
KOILLER, B ;
DAVIDOVICH, MAM ;
FALICOV, LM .
PHYSICAL REVIEW B, 1990, 41 (06) :3670-3677
[17]   LONG-RANGE ORDER IN ALXGA1-XAS [J].
KUAN, TS ;
KUECH, TF ;
WANG, WI ;
WILKIE, EL .
PHYSICAL REVIEW LETTERS, 1985, 54 (03) :201-204
[18]   DEPENDENCE OF THE ALXGA1-XAS BAND EDGE ON ALLOY COMPOSITION BASED ON THE ABSOLUTE MEASUREMENT OF X [J].
KUECH, TF ;
WOLFORD, DJ ;
POTEMSKI, R ;
BRADLEY, JA ;
KELLEHER, KH ;
YAN, D ;
FARRELL, JP ;
LESSER, PMS ;
POLLAK, FH .
APPLIED PHYSICS LETTERS, 1987, 51 (07) :505-507
[19]   REDUCED SYMMETRY AND THE BAND-STRUCTURE OF SEMICONDUCTOR ALLOYS [J].
LING, MF ;
MILLER, DJ .
PHYSICAL REVIEW B, 1986, 34 (10) :7388-7390
[20]   THERMODYNAMIC INSTABILITY OF ORDERED (001) ALGAAS2 IN BULK FORM [J].
MAGRI, R ;
ZUNGER, A .
PHYSICAL REVIEW B, 1991, 43 (02) :1584-1592