"

Cookies ussage consent

Our site saves small pieces of text information (cookies) on your device in order to deliver better content and for statistical purposes. You can disable the usage of cookies by changing the settings of your browser. By browsing our site without changing the browser settings you grant us permission to store that information on your device.

I agree, do not show this message again.

MECHANISM OF PHOTOLUMINESCENCE IN HYDROGENATED AMORPHOUS SILICON DETERMINED BY WIDE-BAND QUADRATURE FREQUENCY-RESOLVED SPECTROSCOPY (QFRS)

T. Aoki1,* , T. Shimizu1, D. Saito1, K. Ikeda1

Affiliation

  1. Department of Electronics and Computer Engineering, and Joint Research Centre of High-technology, Tokyo Polytechnic University (formerly Tokyo Institute of Polytechnics), Atsugi 243-0297, Japan

Abstract

A triple-peak photoluminescence (PL) lifetime distribution is found for a-Si:H at low temperature and low photogeneration rates (geminate condition) by quadrature frequency resolved spectroscopy (QFRS). Using a newly developed wide-band QFRS technique allowing analysis over almost 11 decades in time (2 ns to 160 s), a third lifetime peak, in addition to the well-known double lifetime peaks, is observed in the range 0.1–160 s, and is attributed to distant-pair recombination based on the temperature and generation rate dependence. These results suggest the coexistence of exciton and distant pair recombination even under the geminate condition. At higher temperatures, the distribution becomes a double-peaked one, with peaks due to geminate (non-excitonic) and non-geminate (distant pair) recombination. The discrepancy between the present results and previous simulations suggests that Coulomb interaction should be included in simulations for a-Si:H, to more precisely account for the experimental observations. The effect of an external magnetic field on the lifetime distribution also supports the involvement of exciton and distant-pair recombination under the geminate condition at low temperature..

Keywords

Exciton, Distant-pair, Lifetime, Coulomb interaction, Spin, Magnetic field.

Submitted at: Dec. 9, 2004
Accepted at: Jan. 26, 2005

Citation

T. Aoki, T. Shimizu, D. Saito, K. Ikeda, MECHANISM OF PHOTOLUMINESCENCE IN HYDROGENATED AMORPHOUS SILICON DETERMINED BY WIDE-BAND QUADRATURE FREQUENCY-RESOLVED SPECTROSCOPY (QFRS), Journal of Optoelectronics and Advanced Materials Vol. 7, Iss. 1, pp. 137-144 (2005)