Electrical properties of photogalvanic element with built-in posistor layer based on polymer nanocomposite with carbon filler

• Main Authors: Ivanchenko A. V., Tonkoshkur A. S.
• Format: Article
• Language: English
• Published: Politehperiodika 2020-08-01
• Series: Tekhnologiya i Konstruirovanie v Elektronnoi Apparature
• Subjects: photovoltaic cell; electrical overvoltage; kinetics; electrical characteristics; posistor polymer nanocomposite; tripping temperature
• Online Access: http://tkea.com.ua/journalarchive/2020_1-2/5.pdf
• ISSN: 2225-5818; 2309-9992

The study considers the problem of preventing overheat and thermal breakdown of a photovoltaic cell when a high reverse voltage is applied to its p—n junction. The overvoltage protection ability of a structure made up of a photovoltaic cell in direct thermal contact with a built-in posistor layer has been experimentally studied. Fragments of solar cells based on single-crystal silicon were used as a photovoltaic cells. The posistor layer was a polymer nanocomposite with carbon filler used in the resettable fuses of the “PolySwitch” technology. The authors study kinetics of changes in the electrical characteristics of such a structure under constant electric overvoltage on a shaded photovoltaic cell, when its p—n junction is turned on in the reverse direction. It is shown that the current and reverse voltage on the shaded photovoltaic cell are limited and reduced from the moment when the temperature of this structure reaches the values close to the temperature of the phase transition of the posistor nanocomposite to the low-conductive state, which is ≈ 125°С. With an increase in the overvoltage value, a decrease in the response time of the considered protection and an increase in the maximum current value through the structure under study are observed. A decrease in the current value required to reach the tripping temperature by the posistor layer can be achieved by reducing the thermal resistance of the contact between the photovoltaic and posistor elements of the structure. The results obtained indicate the possibility of implementing protection against reverse electrical overvoltage and thermal breakdown of photovoltaic systems based on photovoltaic cells with built-in fuse layers of a specified type.