фотонное эхо как метод диагностирования возможностей ловушек экситонов и трионов в наноэлектронном приборостроении

Abstract

Предлагается обзор экспериментальных исследований процессов, протекающих в ловушках экситонов и трионов, на основе регистрации характеристик фотонного эха, формируемого на дискретных уровнях квантово-размерных объектов, представленных наноразмерными ловушками экситонов и трионов. На основе регистрируемых характеристик фотонного эха предлагаются новые физические принципы построения наноэлектронных приборов. В том числе, при формировании фотонного эха под воздействием продольного однородного магнитного поля показана возможность определения наполняемости ловушек трионами, а также прямой регистрации фемтосекундных временных интервалов. Paper presents a review of experimental studies into the creation of nano-sized traps of excitons and trions with the use of magnetron sputtering. Besides, the research focused on the processes occurring in the traps by the method of photon echo to reveal the properties that shape new physical principles of nanoelectronic devices. In these traps, with the use of photon echo, there were found the properties of quantum-size discretization of energy by spherical harmonics, which demonstrates a new kind of quantum dots. The aim of the research was to investigate the photon echo as a method for analyzing the capabilities of exciton and trion traps in the development of new physical principles for developing state-of-the-art nanoelectronic devices. Methods. The implemented physical principle of registration of time intervals is based on the conversion of the time interval between the exciting laser pulses into the value of the non-Faraday rotation of the polarization plane of the stimulated photon echo. The registered time interval is more than 2 orders of magnitude shorter than the time intervals registered according to other principles used by the laboratory of fast processes at the All-Russian Research Institute for Optical and Physical Measurements Federal State Unitary Enterprise (VNIIOFI), which develops and stores standards of optically measured quantities. Findings. We formulated and experimentally implemented the principles of creating nano-sized traps of exciton and trion states excited at a room temperature in a semiconductor film. Various physical states of these quasiparticles were registered, which are different in the spectrum of the generated photon echo and relaxation times measured by the optical echo spectroscopy. The measured relaxation times vary from hundreds of femtoseconds to 1 ps. There was also exhibited the physical principle of direct registration of femtosecond time intervals between laser pulses, exciting a stimulated photon echo at the quantized energy levels in the trap. In the trion traps of thin zinc oxide films, the interval reached 27 fs. It was shown that the polarity of the applied longitudinal uniform magnetic field affects the trion states shaped in the trap.