Mutual Passivation in Dilulte GaNxAs1-x Alloys

Conference · Mon Mar 21 04:00:00 EST 2005

OSTI ID:908161

Yu, K M; Walukiewicz, W; Wu, J; Mars, D E; Scarpulla, M A; Dubon, O D; Ridgway, M C; Geisz, J F

The dilute GaN{sub x}As{sub 1-x} alloys (with x up to 0.05) have exhibited many unusual properties as compared to the conventional binary and ternary semiconductor alloys. We report on a new effect in the GaN{sub x}As{sub 1-x} alloy system in which electrically active substitutional group IV donors and isoelectronic N atoms passivate each other's activity. This mutual passivation occurs in dilute GaN{sub x}As{sub 1-x} doped with group IV donors through the formation of nearest neighbor IV{sub Ga-}N{sub As} pairs when the samples are annealed under conditions such that the diffusion length of the donors is greater than or equal to the average distance between donor and N atoms. The passivation of the shallow donors and the N{sub As} atoms is manifested in a drastic reduction in the free electron concentration and, simultaneously, an increase in the fundamental band gap. This mutual passivation effect is demonstrated in both Si and Ge doped GaN{sub x}As{sub 1-x} alloys. Analytical calculations of the passivation process based on Ga vacancies mediated diffusion show good agreement with the experimental results.

• Research Organization: Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
• Sponsoring Organization: USDOE Director. Office of Science. Office of High Energy andNuclear Physics. Office of Basic Energy Sciences. Materials Sciences andEngineering Division
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 908161
• Report Number(s): LBNL--57336; BnR: KC0201030
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALLOY SYSTEMS
ALLOYS
ATOMS
DIFFUSION
DIFFUSION LENGTH
ELECTRONS
PASSIVATION
VACANCIES