Field induced hot-electron emission from quasi one-dimensional nanostructures of wide band gap semiconductors

In recent years, many experimental studies are reported on field electron emission from semiconductor nanostructures, but the related theoretical study is lacking behind. Thus, a number of important experimental observations are not physically explained; these include nonlinear plots on FN coordinates and extremely large field enhancement factors (beta FN) determined by fitting based FN theory. In this work, the above two phenomena are explained theoretically by adapting the field induced hot electron emission model. R. V. Latham, et al. [1995] proposed the hot electron emission model, and later K. H. Bayliss et al. [1986] developed it to explain the observed field electron energy spectra. N. S. Xu et al. [1986] further developed the model by introducing the expression of "effective temperature" into the field emission I-V characteristic, and to explain the emission pattern from a metal-insulator-metal microstructure. All the above results has been called Latham-Bayliss-Xu (LBX) model [2001]. We consider the penetration of electric field into a quasi one-dimensional nanostructure of wide band gap semiconductor and its \´heating effect\´ to electrons. Because of \´heating effect\´ of penetration field, the average energy of electrons can be higher than that of no external field. This higher energy can be expressed by effective temperature T_e of electrons, which is much higher than the temperature of bulk of the emitter. Using the effective temperature in thermal emission j-E expression and Murphy and Good j-E expression in low field and relatively high field cases, the relation between emission current density (j) and external field (E) is described and the field enhancement factor (beta_tau) is calculated quantitatively.