Ordering-induced band structure effects in GaInP2 studied by ballistic electron emission microscopy

We have analyzed the second voltage derivative (SD) of the ballistic electron emission microscopy (BEEM) spectra of GaInP2. We associate two peaks observed in the SD-BEEM spectra of disordered GaInP2 on n+ GaAs substrate with the Γ and L conduction minima, Δ(Γ−L)∼0.35 eV. An additional third peak appearing in the SD-BEEM spectrum of ordered GaInP2 (η∼0.5) is associated with the L-band splitting due to the ordering-induced “folding” of one of the four L valleys onto the Γ̄ point. According to our results, this splitting is ∼ 0.13 eV.