GaAs and GaP make solid solutions that have the same crystal structure as the parent materials, with As and P randomly distributed throughout the crystal. \(\mathrm{GaP}_{x} \mathrm{As}_{1-x}\) exists for any value of x. If we assume that the band gap varies linearly with composition between x = 0 and x = 1, estimate the band gap for \(\mathrm{GaP}_{0.5} \mathrm{As}_{0.5}\). (GaAs and GaP band gaps are 1.43 eV and 2.26 eV, respectively.) What wavelength of light does this correspond to?
Text Transcription:
GaP_x As_1-x
GaP_0.5 As_0.5
SecondLawofThermodynamic(part2) ∮ = 0 in general So, the path from point 1 to point 2 is independent which turns out thais the differential of the state function S. Therefore, dS can be computed for any reversible process of any path chosen. ≡ So, 2 ∆ = 2− 1 ∫ 1 ∆ is the same for any process, whether it is reversible or not, that connects point 1 and 2. When notating with molar, the notation and uni is ∆ = is comparison to ∆ = . Equation of different processes: 1. Cyclic process: S is a state function, therefore ∆ = 0 for any cyclic process. 2. Reversible adiabatic process: For th 0 because it is adiabatic, so ∆ = 0 3. Reversible Phase changes at constant pressure and temperature: Constant T: ∫ 2 = 1 Sin
