Radiative recombination between two dimensional electron gas and photoexcited holes in modulation-doped Al{sub x}Ga{sub 1-x}N/GaN heterostructures

Conference · Sat Jul 01 04:00:00 EDT 2000

OSTI ID:20104620

Shen, B; Someya, T; Moriwaki, O; Arakawa, Y

Photoluminescence (PL) of modulation-doped Al{sub 0.22}Ga{sub 0.78}N/GaN heterostructures was investigated. The PL peak related to recombination between the two-dimensional electron gases (2DEG) and photoexcited holes is located at 3.448 eV at 40 K, which is 45 meV below the free excitons (FE) emission in GaN. The peak can be observed at temperatures as high as 80 K. The intensity of the 2DEG PL peak is enhanced significantly by incorporating a thin Al{sub 0.12}Ga{sub 0.88}N layer into the GaN layer near the heterointerface to suppress the diffusion of photoexcited holes. The energy separation of the 2DEG peak and the GaN FE emission decreases with increasing temperature. Meanwhile, the 2DEG peak energy increases with increasing excitation intensity. These results are attributed to the screening effect of electrons on the bending of the conduction band at the heterointerface, which becomes stronger when temperature or excitation intensity is increased.

• Research Organization: Univ. of Tokyo, Minato (JP)
• OSTI ID: 20104620
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM NITRIDES
COMPOSITE MATERIALS
ELECTRON GAS
EXPERIMENTAL DATA
GALLIUM NITRIDES
HOLES
PHOTOLUMINESCENCE
TEMPERATURE DEPENDENCE
THIN FILMS