Hole effective mass

Near k = 0 the electron and hole effective masses must be isotropic and constant. For a nanoparticle, the uncertainty in the exciton position depends upon its size. Ax 2R. If the relation between energy and momentum is independent of particle size the exciton... 

Enright B, Fitzmaurice D (1996) Spectroscopic determination of electron and hole effective masses in a nanociystalline semiconductor film J Phys Chem 100 1027-1035... 

The other semiconductor, apart from CdSe, that has been studied with deliberate emphasis on quantum size effects, is PbSe (see Table 10.3). There are several reasons for this. One is the long-known use of CD to deposit PbS and later PbSe. Second, and of particular importance, the electron/hole effective mass in PbSe is very... 

Here (oep = eB/m c, m is the hole effective mass, and zp, the hole relaxation time. The total current is simply the sum of the individual currents ... 

Here k is the Fermi wave vector determined from the value of the hole concentration p assuming a spherical Fermi surface, m is the hole effective mass taken as 0.5/no (mo is the free electron mass), is the exchange integral between the holes and the Mn spins, and h is Planck s constant. The transverse and longitudinal magnetic susceptibilities are determined from the magnetotransport data according to x = 3M/dB and xh = M/B. 

The contribution of the hole band is described by the similar formula with the hole effective mass m h, and the energy difference in (25) is ri/,- — E — cmax where emax is the maximum energy of the highest valence band 8E EW, Ew is its width of the valence band. 

TABLE 3 Electron and hole effective masses in InN in units of mo. 

A6.4 Luttinger and Bir-Pikus parameters of GaN and AIN A6.5 Electron and hole effective masses of GaN and AIN A6.6 Deformation potentials of GaN and AIN A6.7 Momentum matrix elements of GaN A6.8 Subband structures of GaN/AlGaN quantum wells A6.9 Optical gain of bulk GaN and GaN/AlGaN quantum wells... 

TABLE 3 Hole effective masses (mo) of wurtzite GaN and AIN. The superscripts L and stand for the perpendicular and parallel to the kz direction, respectively. m h denotes the density of states effective mass, which is evaluated according to m h = (nrjmn)13. HH, LH and CH denote heavy, light and crystal-field split-off hole masses, respectively. 

TABLE 5 Experimentally observed hole effective masses (mo) of wurtzite GaN. m h and m denote the density of states hole mass and its perpendicular component (hole mass in kx-ky plane). 

Of course, the details of the gain spectra depend on the dimensionality of the active material (bulk, quantum well, etc.) and on the details of the band structure. For such detailed calculations we refer to Chapter A6 of this volume. However, it is important to note that due to the specific band structure of the nitrides, the carrier densities needed to achieve inversion and optical gain are very large compared to other m-V semiconductors. In particular, both the electron effective mass (nw = 0.22 [7]) as well as the hole effective mass (mi, 2.0 [8-10]) are three- to four-fold larger than in GaAs. For the same reason, however, the maximum gain obtainable from nitride structures is also larger. 

The energy bands are no longer described by the -k dispersion relations, but instead by a density-of-states distribution N E), illustrated in Fig. 1.6. Also the electron and hole effective masses must be redefined as they are usually expressed as the ciu-vature of (k). 

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