Experimental and Theoretical Studies of Hydrogenated Amorphous Semiconductor Alloys and Superlattices
Abstract
We developed the photocarrier grating technique for carrier mobility- lifetime products (micro-Tau) measurements. Applying this technique to hydrogenated amorphous silicon (a-Si:H), we obtained micro-Tau values ranging from 10(exp-8) to 10(exp-5) sq cm/V for the majority and 10(exp-10) - 10(exp-8) for the minority carrier. This served as a basis for quality evaluation of prepared by different methods. We established that the dominant recombination mechanism is the 'defect pool' mechanism. Using the semiconductor-electrolyte system, we studied the density of localized states in a-Si-H and compared it to crystalline silicon. We found in a-Si:H an overall density of localized states in 10(exp-18) /cu cm. In crystalline Si only surface states were found, of an overall density of 10(exp-12) sq/cm. The sq cm states are centered around 0.2 eV the conduction band edge. The transport properties of two other disordered systems that may be relevant to a-Si-H were studied theoretically. These systems consists of metal cermets and of small colloidal suspensions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 04, 1994
- Accession Number
- ADA276159
Entities
People
- G. Morell
- I. Balberg
- J. Penalbert
- M. H. Farias
- Manuel Gomez
- Nicole Yasmin Wagner
- O. Resto
- W. Munoz
- Zvi S. Weisz
Organizations
- University of Puerto Rico