Ti-Doped ZnO Thin Films-Based Transparent Photovoltaic for High-Performance Broadband and Wide-Field-of-View Photocommunication Window

Abstract

Transparent photovoltaics (TPVs) are crucial for developing next-generation see-through electronics. However, TPV devices (TPVDs) require wide-bandgap materials that are typically only responsive to short wavelength (ultraviolet, UV) lights rather than visible lights. Is it possible to improve the TPV performance by harvesting the longer wavelength lights without degradation of transparency? It may be satisfied with the function of intermediate energy states, which can utilize the lower photon energy (longer wavelength light) by a two-step transition. To achieve this, co-sputtered Ti-doped ZnO (Ti:ZnO) film-based high-performance TPVDs have been developed. Density functional theory analysis revealed the formation of intermediate energy states due to the hybridization of O 2p and Ti 3d orbitals in the Ti:ZnO system. The Ti:ZnO-based TPVDs show 65% average visible transparency with a power production value of 655 μW cm⁻². These devices exhibit good photodetection behavior under UV to visible illuminations with high responsivity and detectivity values of 1.85 A W⁻¹ and 2.5 × 10¹³ Jones, respectively. Finally, a high-performance UV to visible broadband and wide-field-of-view photocommunication system is designed based on the TPVDs to generate the fast Morse code signal. Therefore, Ti doping in ZnO provides a good way to improve the device's functionality for futuristic applications.