The different physical origins of 1/f noise and superimposed RTS noise in light-emitting quantum dot diodes

Low frequency noise characteristics of light-emitting diodes with InAs quantum dots in GaInAs layer are investigated. Two noise components were found in experimental noise records: RTS, caused by burst noise, and 1/f Gaussian noise. Extraction of burst noise component from Gaussian noise background was performed using standard signal detection theory and advanced signal-processing techniques. It was found that Hooge's empirical relation applied to diodes by Kleinpenning is applicable to the electric 1/f noise in quantum dot diodes as well. Two different spectra decomposition techniques are used to obtain burst noise spectra. Bias dependences of burst and 1/f noise are compared. It is concluded that the RTS noise and 1/f noise have different physical origins in light-emitting diodes with quantum dots

Сurrent problems in energetic materials ignition studies

Several problems of ignition of energetic materials (EMs), which are able to burn in the absence of an external oxidizer, are discussed in this chapter. Scientific investigation of the EMs ignition has started at the end 1930th when the first field missiles (Katyusha) were developed in the USSR. Later the investigations were actively performed in USA and Europe but despite rather long history there still remain unsolved problems related to complete description of nonstationary transition to self-sustaining combustion, correct determination of the ignition moment, determination of the EM high-temperature reaction kinetics, etc. In the early studies, the limiting cases of the EM ignition solely due to exothermic reactions either in the condensed or gas phase were investigated but later it was revealed that formany EMs such reactions can proceed simultaneously in both phases. This implies the necessity of analyzing the ignition mechanisms involving reactions in the condensed as well as in the gas phase. In this chapter, the attention is paid to theoretical description of transient burning rate behavior of the EMs exothermically reacting in both phases, to the formulation of ignition criterion and to the experimental methods of measuring transient burning rate. In addition, the problems of correct determination of the EMs high-temperature kinetics are discussed as well as the problems of ignition of EMs with shielded reacting surface (opaque and semitransparent substances). Obviously, due to restricted volume, the chapter could not answer all questions but its content may become useful for researchers working in this field in order to better understand state of the art of EMs ignition studies and better plan some future researches in this direction