Deep-level transient spectroscopy characterization

Lang, D. V. 1974. Deep-level transient spectroscopy A new method to characterize traps in semiconductors. J. Appl. Phys. 45 3023-3032. 

Kuranouchi, S. Konagai, M. 1995. Characterization of ZnO/CdS/CuInSe2 thin-film solar cells by deep-level transient spectroscopy. Jpn. J. Appl. Phys. 34 2350-2351. 

Characterization of radiation-induced centers in the p -n-structures was carried out by means of deep level transient spectroscopy (DLTS) [3]. Concentrations, activation energies of charge carrier emission, and apparent capture cross sections of carriers were determined for all the traps observed. 

A few selected techniques that are representative of recent advances are described as examples of the much broader field of semiconductor electrical characterization. In particular, resistivity, carrier concentration, junction depth, generation/recombination lifetime, deep level transient spectroscopy and NOSFET mobility measurements are discussed. The importance of non-contacting methods is stressed and recent trends in this direction are outlined. This paper serves as an introduction to some of the following papers in this volume. 

Optical techniques like photoluminescence (10) and infrared photothermal spectroscopy (11.) work well for the characterization of shallow level impurities, while electrical techniques work well for deep level impurities. There are a number of methods that have been used for electrical characterization. I will only discuss deep level transient spectroscopy (DLTS), however, because it has become the most popular and gives a fairly complete characterization. 

D.V. Lang, Deep level transient spectroscopy—new method to characterize traps in semiconductors ,/. Appl. Fbys., 45, 3023, (1974). 

There are some techniques, such as admittance spectroscopy and deep-level transient spectroscopy (DLTS), that are quite powerful in the characterization of deep levels in semiconductors [139]. These techniques have also begun to be used for the characterization of conjugated polymers such as PPV [178] and MEH-PPV [179]. These techniques may permit the determination of several trap parameters such as activation energy, concentration, charge carrier capture cross section, defect donor/acceptor character that can contribute to the chemical identification of the traps. 

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