Electronic Transitions in Mixed Phase Crystalline/Amorphous Silicon in the Low Crystalline Fraction Regime

Autor:	E. P. Hollar, Daewon Kwon, John R. Abelson, Ian M. Robertson, J. David Cohen, Hyun-Chul Jin, Chih-Chiang Chen
Rok vydání:	1999
Předmět:	Amorphous silicon Materials science Condensed matter physics Silicon business.industry Photoconductivity Nanocrystalline silicon chemistry.chemical_element Crystallographic defect Amorphous solid chemistry.chemical_compound Amorphous carbon chemistry Optoelectronics Crystallite business
Zdroj:	MRS Proceedings. 557
ISSN:	1946-4274 0272-9172
DOI:	10.1557/proc-557-495
Popis:	Amorphous silicon films were prepared by dc reactive magnetron sputtering under conditions approaching the phase transition to microcrystallinity. Using TEM imaging these films were found to contain clusters of 5 to 50 nm sized Si crystallites embedded in an amorphous silicon matrix. Photocapacitance and transient photocurrent sub-band-gap optical spectra of this material appear to consist of a superposition of a spectrum typical of amorphous silicon together with an optical transition, with a threshold near 1. 1eV, that exhibits a very large optical cross section. This transition arises from valence band electrons being optically inserted into empty levels lying within the amorphous silicon mobility gap. Using modulated photocurrent methods we have determined that these states also dominate the electron deep trapping in this material. We argue that these states arise from defects at the crystalline-amorphous boundary.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::02ec3b516f0be7782540d3c637e48e18 https://doi.org/10.1557/proc-557-495 Zobrazit plný text záznamu Full text from SpringerLink