Characteristics of the oxide- p -InSe heterojunctions exposed to irradiation with X-ray photons
- PDF / 206,184 Bytes
- 4 Pages / 612 x 792 pts (letter) Page_size
- 8 Downloads / 144 Views
CONDUCTOR STRUCTURES, INTERFACES, AND SURFACES
Characteristics of the Oxide–p-InSe Heterojunctions Exposed to Irradiation with X-ray Photons Z. D. Kovalyuka^, V. N. Katerynchuka, O. A. Politanskaa, and N. D. Raranskyb aFrantsevich
Institute of Problems in Materials Science, National Academy of Sciences of Ukraine, Chernovtsy, 58001 Ukraine ^e-mail: [email protected] bFed’kovich National University, Chernovtsy, 58012 Ukraine Submitted July 19, 2005; accepted for publication September 14, 2005
Abstract—It is established that the characteristic X-ray radiation (with the wavelength λ = 0.056 nm) affects the photoelectric parameters of heterojunctions formed of the native thermal oxide and p-InSe. The current– voltage and spectral characteristics of the structure prior to and after irradiation are studied. The observed variations in the open-circuit voltage, short-circuit current, current–voltage characteristics, and the photosensitivity spectra of heterojunctions are caused by formation of radiation defects in InSe. These defects bring about an increase in the rate of recombination processes in the charge-transport mechanisms, slightly affect the surfacerecombination rate, and do not exert a destructive effect on the value of the contact-difference potentials. The results obtained are accounted for in the context of an electrostatic model of formation of radiation defects in the crystal lattice. PACS numbers: 73.40.Lq, 73.50.Pz, 61.80.Cb DOI: 10.1134/S1063782606080094
1. INTRODUCTION It may so happen that semiconductor optoelectronic devices operate under conditions of irradiation with high-energy particles or photons. In this case, the electrical characteristics of the base crystals in these devices can remain intact or vary depending on the duration of irradiation and also on the intensity and energy of radiation. Establishing trends in the variations of the parameters of these devices can be used to correct their operation. Si, Ge, and GaAs semiconductors and the structures based on these materials are objects of studies concerning radiation resistance. However, there exists a whole class of layered III–VI semiconductors with the band gap (Eg) close to that of the above-mentioned classical semiconductors. For example, the compound InSe (Eg = 1.2 eV at 300 K) can serve as an analogue of silicon and as an alternative to silicon from the standpoint of radiation resistance. The anisotropy of chemical bonds plays a basic role in determining the physical properties of layered semiconductors and differentiating them from other solids [1]. The crystalline structure of indium monoselenide is represented by a sequence of layers each of which consists of four densely packed single-atom sublayers arranged in the sequence of Se–In–In–Se [2]. It is also characteristic that there is a strong covalent bonding within layers and weak Van der Waals bonding between the layers. Such a structure gives rise to a number of modifications that differ insignificantly from each other with
respect to the formation energy. The possibility o
Data Loading...
