DESIGN AND DEVELOPMENT OF CMOS-BASED PEROVSKITE PHOTOVOLTAIC CELL(S) DEGRADATION DETECTION SYSTEM

Abstract

The digitization and automation of processes (industrial, commercial and domestic) remain a viable venture in the 21st century. This engenders the idea of the interconnection of communication and sensing nodes in the internet of things (IoT) paradigm. The application of sensing nodes is prevalent and this trend will continue as the miniaturization of electronic devices persists. These nodes and devices depend primarily on electrical energy, which in most cases is provided by batteries (rechargeable and non-rechargeable) or other conventional energy sources such as fossil fuels. The use of such energy sources has resulted in the exacerbating climate change plaguing the world currently. Renewable energy sources such as wind, hydro, geothermal and solar, are considered the alternatives to remedy this situation. Solar energy is always an attractive option due to its abundance in nature, cleanliness and ease of harnessing. Photovoltaic (PV) cells are used to collect solar energy and convert it to electricity. To date, the standard silicon PV cell continues to dominate solar energy due to its reliability and durability even in extreme atmospheric conditions. However, its poor power conversion efficiency (PCE) poses a difficult challenge. Perovskite solar cells (PSC) outshine the standard silicon photovoltaics in terms of flexibility, power conversion efficiency (PCE) and compatibility with microelectronic devices. However, its stability and durability under atmospheric conditions present some constraints. Also, the possibility of lead poisoning emanating from the degradation of the perovskite structure cannot be ignored. This thesis work presents a novel degradation detection system for PSC in integrated applications. The proposed system comprises a PSC; the specimen under observation, a Transimpedance Amplifier (TIA), an 8-bit Successive Approximation Register Analog-to-Digital Converter SAR-ADC and an output front end. A transimpedance amplifier employing an inverting operational amplifier configuration is designed to sense the output current of the specimen (PSC) and convert it to a voltage signal for further processing. The 8-bit SAR-ADC design forms a part of the data processing unit of the sensing architecture. It converts the analog voltage signal received from the TIA to a digital voltage signal for the output front end. The output front end is the latter part of the system, and it comprises an output register and an ideal DAC. The ideal DAC is provided with a voltage reference upon which the final output decision is made. The final output decision of the system indicates the status of the PSC. Each of the circuit blocks is designed and implemented in the gpdk90nm CMOS process in Cadence. Keywords: Renewable energy, Perovskite Solar Cells, Power Conversion Efficiency, TIA, SARADC.