World Journal of Engineering Research and Technology

Prof. Dr. Huynh Van Cong*

ABSTRACT

In Ge(1-x)Si(x) [ Si(1-x)Ge(x)]- crystalline alloys, , taking into account their different values of energy-band-structure parameters, as given in Table 1, and also basing on the same physical model and mathematical treatment method, as used in our recent works[1, 2, 3], various electrical-and-thermoelectric laws, relations, and coefficients, enhanced by our static dielectric constant law given in Equations (1a, 1b), which is due to the effects of the size of donor (acceptor) d(a)-radius and the x-concentration, by our accurate Fermi energy, as given in Eq. (11), and finally by our electrical conductivity model, as given in Eq. (14), are now investigated. One notes that, for x=0, their obtained numerical results are reduced to those obtained in the n(p)-type degenerate Ge(Si)-crystals.[4,5] So, some remarkable results can be cited as follows. In Tables 5n(5p), for a given impurity-density and with increasing temperature T, and then in Tables 6n(6p), for a given and with decreasing N, the reduced Fermi-energy decreases, and other thermoelectric coefficients are in variations, as indicated by the arrows by: (increase: , decrease: ). Furthermore, one notes in these Tables that, for any given x, and N (or T), with increasing T (or decreasing N) one obtains: (i) for , while the numerical results of the Seebeck coefficient S present a same minimum , those of the figure of merit ZT show a same maximum , (ii) for , the numerical results of S, ZT, the Mott figure of merit , the first Van-Cong coefficient VC1, and the Thomson coefficient present the same results: , 0.715, 3.290, , and , respectively, and finally (iii) for , . It seems that these same obtained results could represent a new law in the thermoelectric properties, obtained in the degenerate case ( ).

[Full Text Article] [Download Certificate]