Photo‐Induced Metastable Effects in Hydrogenated Amorphous Silicon (a‐Si:H)

Abstract

A b s t r a c t . Light induced changes of electronic properties are studied in glow discharge deposited a-Si: H-films by ESR, field effect, DLTS and elect,ronir transport. These effects are caused by silicon da,ngling bonds generated by recombination processes, which raise the density of states near midga,p. The concomitant, increase of potential fluctuations indicates that these defects are inhomogeneously distribnted. Licht-induzierte metastabile Effekte in hydrogenisiertem amorphem Silizium (a-Si : H)Inlial t s u bersicht. Es wird uber Licht-induzierte Anderungender elektronischenEigenscha.ft.en von a&: H-Filmen berichtet. Dazu wurde der EinfluD liingerer Belichtung auf ESR, Feldeffekt, DLTS und Transporteigenschaftsn untersucht. Die metastabilen Effekte entstehen durch freie Si-Bindungen, die bei der Rekombination gebildet werden und zu einer Erhohung der Zustandsdiclite nahe der Mitte der verbotenen Zone fuhren. Die dabei auftretende Verstarkung von Potentialfluktuntionen dentet darauf hin, daB diese Defekte inhomogen verteilt sind.

Light-induced modification of a-SiOx II: Laser crystallization

“…The effects of intensive illumination generally are detrimental for the properties of amorphous or glassy semiconductors as a result of light-induced degradation effects. [1][2][3][4][5][6][7][8] However, under certain circumstances strong irradiation can also help to modify and enhance the material quality in a desired way. In the case of amorphous silicon, if the intensity of the incident light is strong enough to melt the amorphous film ͑partly or completely͒, it can form ͑poly-͒crystalline material upon solidification.…”