Regular Article

Enhancement of thermionic emission by light

¹ Centre for Energy Studies, Indian Institute of Technology, New Delhi 110016, India
² Department of Education Building, Room 212, Lucknow University, Lucknow 226007, India

^a e-mail: msodha@rediffmail.com

Received: 28 May 2016
Revised: 28 December 2016
Accepted: 19 January 2017
Published online: 3 March 2017

Abstract

In this paper the rate of electron emission from an illuminated hot metallic plate has been evaluated on the basis of the free electron theory of metals and Fowler’s theory of photoelectric electron emission. The modification of the electron energy distribution (or enhancement of electron temperature) in the plate by energetic electrons (which get their normal energy enhanced on the surface by incident photons of frequency below threshold and are not emitted) has been taken into account. The thermionic current as modified by the electron temperature so enhanced by irradiation has been evaluated. The results may be applicable to thermionic convertors, as proposed to be operated by Schwede et al. [J.W. Schwede, I. Bargatin, D.C. Riley, B.E. Hardin, S.J. Rosenthal, Y. Sun, F. Schmitt, P. Pianette, R.T. Howe, Z. Shen, N.A. Melosh, Nat. Mater. 9, 762 (2010)]. Numerical results have been presented and discussed.