Doping acceptor density

In Ref. 54, XRD showed the deposit to be hexagonal CuSe. Analysis of the absorption spectrum gave a direct bandgap of 2.02 eV. As commonly seen for these compounds, there was still strong absorption at lower energies (e.g., at 1.9 eV, the absorption coefficient was >7 X 10" cm ), possibly due to an indirect transition but likely due, at least in part, to free-carrier absorption. From Hall measurements, the doping (acceptor) density was ca. 10 cm (heavily degenerate) and the mobility ca. 1 cm V sec The dependence of film thickness and deposition rate on the deposition parameters has been studied in a separate paper [62]. 

By doping, the density of one type of carrier is increased at the expense of the other type. In fact n-type materials are made by incorporating donors. If the electrons are mobile, they are good electron conductors and poor hole conductors. On the other hand, p-type materials are made by incorporating acceptors. If the holes are mobile, they are good hole conductors and poor electron conductors. We shall see that these properties are extremely important for the functioning of a solar cell. 

Doping a p-type semiconductor generates fixed acceptor sites with a density Na, and an equal number of mobile carriers with an opposite charge h+, whose distribution is controlled by the local value of the potential T>(x), following the Boltzmann function so that the mobile charge distribution is given by ... 

Electrical conductivity, 319,335,337,339 Electrical properties, 319 Electric displacement, 348 Electric field, 351 Electric flux density, 348 Electric inductive capacity, 287, 319, 326 Electric permittivity, 287 Electric susceptibility, 348, 349 Electrochemical n-doping, 341 p-doping, 341 Electron acceptor, 333 parameter, 242 Electron donor, 333, 337 parameter, 242... 

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