Doctor of Physical and Mathematical Sciences, Professor of the Department of «Professional Education» of the Faculty of Physics and Technology of Fergana State University
Alimov Nodir Esonalievich
Doctor of Philosophy in Physical and Mathematical Sciences, Lecturer at the Department of Physics, Faculty of Physics and Technology, Ferghana State University
Botirov Qodir Abdullayevich
Lecturer of the Department of «Professional Education» of the Faculty of Physics and Technology of Ferghana State University
Ferghana State University, Ferghana, Uzbekistan
Annotation. In this paper, the photoelectric properties of CdTe – SiO2 – Si heterostructures are investigated. For the first time, the possibility of controlling the spectrum of short – circuit current and photo-EMF using an integrated charge in a dielectric (SiO2) has been demonstrated. It was found that with an increase in the corona discharge potential, the spectra will mix into the short – wavelength regions of the spectrum from 0.93 to 1.5 eV, while the activation energy of the deep level of 0.73 eV changes significantly and this change occurs due to the Poole-Frenkel effect. It is found that the electric field strength in the vicinity of the defect is ε = 105 V/cm.
Keywords: photoconductivity, PHOTOEMF, spectral distribution of photosensitivity, short-circuit current, asymmetry of barriers, surface photo-EMF, deep levels, impurity photoconductivity, corona discharge.
Аннотация. В данной работе исследованы фотоэлектрические свойства гетероструктур на основе CdTe – SiO>2 – Si. Впервые продемонстрирована возможность управления спектра тока короткого замыкания и фото – ЭДС при помощи встроенного заряда в диэлектрике (SiO>2). Установлено, что с увеличением потенциала коронного разряда спектры смешается в коротковолновые области спектра от 0,93 до 1,5 эВ, при этом существенно изменяется энергии активации глубокого уровня 0,73 эВ и это изменение возникает за счёт эффекта Пула – Френкеля. Найдено, напряжённость электрического поля в окрестности дефекта ε = 10>5 В/см.
Ключевые слова: фотопроводимость, фото-ЭДС, спектральное распределение фоточувствительности, ток короткого замыкания, асимметрия барьеров, поверхностная фото-ЭДС, глубокие уровни, примесная фотопроводимость, коронный разряд.
Introduction
The development of micro – nano electronics and new technological possibilities for the manufacture of complex semiconductor structures stimulate further study of new optical and photovoltaic phenomena in active film elements.
Currently, oxides and nitrides of semiconductors and semiconductor films grown on their surfaces are widely used in the manufacture of multichannel photovoltaic converters and other active elements of microelectronics circuits, and in particular, optoelectronics. In this case, it is possible to obtain high-quality and dielectric layers of semiconductors with deep levels. At the same time, it is easier and cheaper to use polycrystalline films sprayed on amorphous substrates rather than epitaxial ones.
CdTe semiconductor films are an important material for the creation of photodetector devices based on heterostructures operating in the near (up to 3 microns) and far (8—14 microns) The IR range. It is of interest to obtain heterostructures based on photosensitive layers with different types of conductivity. A promising p-type material doped with silver and copper, which give an acceptor level in the forbidden zone with a long lifetime of non-main charge carriers [1—14].
The aim of the work is to study new photovoltaic properties of active CdTe thin films and heterostructures in a system with SiO2-Si under conditions of specific external influences.