We report on optical spectroscopy (photoluminescence and photoluminescence excitation) on two-dimensional self-organized layers of (C(6)H(5)C(2)H(4)-NH(3))(2)-PbI(4) perovskite. Temperature and excitation power dependance of the optical spectra gives a new insight into the excitonic and the phononic properties of this hybrid organic/inorganic semiconductor. In particular, exciton-phonon interac...

Spatially, spectrally, and temporally resolved cathodoluminescence ~CL! techniques have been employed to examine the optical properties and kinetics of carrier relaxation for metalorganic chemical vapor deposition grown InGaN/GaN single quantum wells ~QWs!. Cathodoluminescence wavelength imaging of the QW sample revealed local band gap variations, indicating the presence of local In composition...

We develop a theory of effects of electron-electron collisions on the Dyakonov-Perel’ spin relaxation in multi-valley quantum wells. It is shown that the electron-electron scattering rate which governs the spin relaxation is different from that in a single-valley system. The theory is applied to Si/SiGe (001)-grown quantum wells where two valleys are simultaneously populated by free carriers. T...

We investigated the high-carrier screening of macroscopic polarization fields in GaN quantum wells (QWs) using a variational wave function for electrons and holes. In particular, we studied of the influence of free-carrier screening on the photoluminescence (PL) energy emission and carrier lifetime in the QW. We show that the energy transition between electrons and holes are explained well by t...

Scanning near-field optical spectroscopy was applied to semipolar ð20 2 1Þ InGaN/GaN quantum wells (QWs) to evaluate spatial homogeneity of QW band gap and its dependence on the growth conditions. In the most uniform QW, photoluminescence (PL) spectra were found to be narrow with small peak wavelength and spectral width variations. A QW grown at reduced temperature showed sub-micrometer size PL...

The relative strengths of Rashba and Dresselhaus terms describing the spin-orbit coupling in semiconductor quantum well (QW) structures are extracted from photocurrent measurements on n-type InAs QWs containing a two-dimensional electron gas (2DEG). This novel technique makes use of the angular distribution of the spin-galvanic effect at certain directions of spin orientation in the plane of a ...

Abstract A drop in the efficiency of light-emitting diodes based on InGaN/GaN QWs known as ‘green gap’ has been studied intensively over past dozen years. Several factors were revealed to contribute its origin, such random fluctuations indium concentration or diffusion point defects during growth QWs. The aim this paper is demonstrate that Kirkendall effect can be mechanism responsible for ther...

The noise of the dark current and photocurrent is an important factor in operation of the quantum well infrared photodetectors ~QWIPs!. For typical operating conditions, the main source of fluctuations in QWIPs is generationrecombination noise associated with the excitation of carriers from the QWs into the continuum and their capture into the QWs. For applications the study of noise in QWIPs i...

We have examined in detail crystal orientation effects on the properties of excitonic emission from wurtzite InxGa1−xN/GaN quantum wells (QWs) with piezoelectric polarization using exciton binding and transition energy calculations based on a single-band effective-mass theory. We show numerical results for the bandgaps, effective heavy-hole masses, piezoelectric polarizations and fields, excito...

It is shown that absorption of circularly polarized infrared radiation due to intraband (Drude-like) transitions in n-type bulk semiconductors and due to intra-subband or inter-subband transitions in quantum well (QW) structures results in a monopolar spin orientation of free electrons. Spin polarization in zinc-blende-structure based QWs is demonstrated by the observation of the spin-galvanic ...