Unexpected band bending at the Au/MAPbI3interface induced by the trapping of holes.

The contributions of the electric-dipole and magnetic-dipole matrix elements to conductionelectron-spin resonance in zinc-blende crystals are investigated theoretically and experimentally. Using time-dependent perturbation analysis, we show that these contributions interfere at the resonance condition, resulting in an anomalous dependence of the resonance intensity on the sign of either the dc magnetic field Bo or the wave vector q of the photon. In the context of macroscopic dielectric response, it is shown that the above interference can be represented by time-reversal symmetry associated with the wave vector. The effects of electric-dipole -magnetic-dipole (EDMD) interference at spin resonance have been studied experimentally by far-infrared (FIR) magnetotransmission in a series of InSb samples with various orientations and electron concentrations. Experiments were performed in magnetic fields up to 60 kG in both Voigt and Faraday geometries, at FIR wavelengths 96.5, 118. 8, 163, and 251.1 pm, in' the temperature range between 2 and 35 K. Measurements of the absorption coefficient as a function of orientation of Bp in (100), (110), (111), and (112) planes, and as a function of the sign of Bo and q, are in excellent agreement with the predictions of the theory. These experiments provide an elegant method for determining the inversionasymmetry parameter 6O, yielding a value of 56 a.u. (3.6&(10 erg cm ). In addition to the EDMD interference, the FIR magnetotransmission spectra also conclusively demonstrate that the dominant mechanism allowing electric-dipole-excited spin resonance in InSb is inversion asymmetry.