Title :
Superlattices and multilayers in hydrogenated amorphous-silicon devices
Author :
Hirose, Masataka ; Miyazaki, Seichi
Author_Institution :
Dept. of Electr. Eng., Hiroshima Univ., Higashi, Japan
fDate :
12/1/1989 12:00:00 AM
Abstract :
An investigation of the physical properties of ultrathin multilayer structures that consist of hydrogenated amorphous silicon (a-Si:H) and silicon-based compounds such as a-Si1-xNx :H and a-Si1-xCx:H prepared by either plasma chemical vapor deposition (CVD) or direct photo-CVD is discussed. X-ray interference in the multilayers shows that the heterojunction interface is atomically flat and abrupt. The band offset is successfully determined by X-ray photoelectron spectroscopy. The energy band profile in the superlattices can therefore be designed. The carrier confinement in the ultrathin a-Si:H layers causes a blue shift of the optical bandgap and luminescence spectrum due to the quantization effects. Better understanding of the quantum size effects in the multilayers permits the introduction of superlattice structures to devices such as solar cells, thin-film transistors, and light-emitting diodes. Some of the experimental results are discussed
Keywords :
CVD coatings; X-ray photoelectron spectra; amorphous semiconductors; elemental semiconductors; energy gap; hydrogen; insulated gate field effect transistors; light emitting diodes; luminescence of inorganic solids; photoluminescence; plasma CVD coatings; semiconductor superlattices; silicon; silicon compounds; size effect; solar cells; thin film transistors; Si:H-Si1-xCx:H; Si:H-Si1-xNx:H multilayers; Si:H-Si3N4:H; X-ray interference; X-ray photoelectron spectroscopy; amorphous semiconductor; band offset; carrier confinement; direct photo-CVD; energy band profile; heterojunction interface; light-emitting diodes; luminescence spectrum; optical bandgap; plasma CVD; plasma chemical vapor deposition; quantization effects; quantum size effects; solar cells; superlattices; thin-film transistors; Amorphous silicon; Chemical vapor deposition; Heterojunctions; Interference; Nonhomogeneous media; Plasma chemistry; Plasma confinement; Plasma properties; Plasma x-ray sources; Superlattices;
Journal_Title :
Electron Devices, IEEE Transactions on