NFC-integrated transparent photovoltaic device for future electronics application

Near-field communication (NFC) technology involves short-range wireless communication between common electronic devices, such as smart cards, car keys, and house and office keys. NFC enables contactless data transfer, secure authentication, and power transfer through electromagnetic fields, greatly facilitating easy and convenient applications and data use. Conversely, transparent photovoltaics (TPVs), which combine visible transparency with solar energy conversion, are being developed for applications where conventional opaque solar cells are unlikely to be feasible, such as building or vehicle windows. This research proposes to combine NFC and TPV to obtain power generation and secure wireless communication in a single device, specifically on a glass substrate, using a sputtering technique. The device will facilitate future electronics to communicate using NFC and TPV cells offer the advantage of harvesting energy in the visible range and blocking harmful ultraviolet radiation from sunlight. In the fabricated NFC-integrated TPV device, an approximately 200 nm thick NFC coil (ITO/Ag) exhibited an inductance of over 2 microhenries at the resonant frequency of 13.56 MHz. This coil can successfully read NFC card and illuminate a red-light-emitting diode using wireless power. Additionally, the titanium-doped zinc oxide (Ti:ZnO) TPV shows approximately 70 % transparency with an open-circuit voltage of 305 mV under 365 nm illumination at an intensity of 38 mW/cm². By exploring innovative fabrication techniques and materials, we aim to develop a multifunctional substrate that efficiently combines functionalities such as wireless communication and power generation for battery-free security locks, energy-efficient smart windows, and other applications, thereby optimizing space utilization and promoting sustainable energy solutions.