Electroreflectance and Wavelength Modulation Study of the Direct and Indirect Fundamental Transition Region of In_1−xGa_xP

Abstract

The direct E,, E, + A , and indirect E r -x transition energies of Ini-,Ga,P crystals are studied by electromodulation and wavelength modulation methods a t 77 K and room temperature. TheE, energy at 77 K and room temperature obeys a parabolic relation as a function of composition x with a bowing parameter of b = 0.764 and 0.76 eV, respectively. The E r -x energy a t 77 K can be expressed by a linear x-dependence with slope 0.072 eV. The crossover point a t 77 K is determined as xc = 0.72 0.015; E , = (2.300 f 0.003) eV. The spin-orbit splitting A, shows an upward bowing with bowing parameter -0.060 eV.

Band parameters for III–V compound semiconductors and their alloys

“…496,497 The X-valley gap energies in InP and GaP are nearly equal ͑2.38 and 2.35 eV, respectively, at 0 K͒, and the ⌫ -X crossover composition in GaInP is believed to be close to x ϭ0.7. 479 Although early work usually assumed a linear 496 and Meney et al 498 Our recommended value of C(E g X )ϭ0.2 eV agrees with other experimental and theoretical results. 482 Early experimental and theoretical determinations of the bowing parameter for the L-valley gap were summarized by Bugajski et al 482 The ⌫ -L crossover most likely occurs at x slightly smaller than the ⌫ -X crossover point, 480 which makes L the lowest conduction valley for x greater than Ϸ0.67.…”

“…Modeling of the ellipsometric and thermoreflectance data of Ozaki et al 500 yielded E g L ϭ2.25 eV in Ga 0.5 In 0.5 P at 300 K, which favors a small L-valley bowing. In deriving our recommended bowing parameter, we employed the ⌫ -L crossover point of xϭ0.67, 482,499 which was confirmed recently by Interholzinger et al 501 The bowing of the spin-orbit splitting in GaInP is known to be very small, 446,476,479 with recent results 502 implying a linear interpolation to within experimental uncertainty.…”

“…467,[474][475][476][477][478] Subsequent electroreflectance and modulation spectroscopy studies favored a value near the higher end of that range. [479][480][481] Theoretical studies have also produced a wide range of bowing parameters, 101,201,410,418,482 with the most reliable results clustered around 0.5-0.75 eV. By analogy to GaInAs and AlInAs, it is useful to consider the Ga 0.51 In 0.49 P alloy for which the most extensive data are available.…”

Effects of crystal ordering and composition on properties of CdSxTe1−x alloys: a first-principle insight

“…This theory predicts positive b(∆ SO ). In order to explain some experimentally observed negative bowing values, 7,8 Wei et al 19 propose that the interband p-p coupling enhances ∆ SO and dominates the value of b(∆ SO ). From their calculated values, in Table 1, for CdS x Te 1−x , the authors find that: (a) the SO splitting shows strong ordering dependence.…”

On the quantitative characterization of chemical disorder of In1−xGaxP from wavelength‐modulated No‐phonon absorption

“…EL = 10meV [lo]. The composition dependences of the direct and indirect gaps of Inl-,Ga,P were taken from [9]. From the fitting procedure we have got for Inl-,Ga,P A, = 1.23 x lo6 cm-l.…”