Silicon is the most commonly employed optoelectronic material, thanks to its high performance, long lifetime, and economic viability. [7,8] However, some fields of photodiodes' possible applications require additional features besides the excellent performance characteristics provided by conventional silicon photodiodes. [9,10] Rapid development of commercial and scientific space programs and large-scale nuclear safety efforts in radioactively contaminated areas presupposes the development of next-generation radiation-resistant optoelectronic materials and devices. [11][12][13][14][15][16] It is known that wide bandgap II-VI compound semiconductors possess a noticeably higher radiation resistance compared to their established commercially available counterparts Ge, Si, and III-V compounds. [17][18][19] For instance, the development of CdTe-base optoelectronic devices has been an active research field for years motivated by the demand for improved radiation hardness. [20][21][22][23] However, CdTe still exhibits only moderate radiation hardness that needs to be improved further to achieve reliable operation in harsh environments. [24,25] It has been shown that Cd 1−x Zn x Te solid solutions (also referred to as CdZnTe) possess much higher radiation resistance than CdTe. [26][27][28][29] As such, CdZnTe is commonly used as the active material for X-and γ-ray detectors. [30,31] The large A novel high-performance ultraviolet-visible-near-infrared (300-820 nm) heterojunction photodiode based on radiation-resistant semiconductor materials is proposed. A titanium nitride (TiN) "window" layer is deposited via magnetron sputtering onto a cadmium zinc telluride (CdZnTe) solid solution single crystal. The TiN/CdZnTe heterojunction photodiodes concurrently reveal an outstanding detectivity, response time, and linear dynamic range outperforming similar heterojunction photodiodes and photodetectors, based on photoactive inorganic compound semiconductor materials. Moreover, the added feature of the proposed heterojunction photodiodes is their excellent radiation resistance, experimentally demonstrated under short impulse proton irradiation (170 keV) with an accumulated fluence of 2 × 10 12 proton cm −2 . This unusual synergy of high performance and advanced radiation resistance of the TiN/CdZnTe photodiodes provides a unique platform for operation in space or radioactively contaminated environments.