In this contribution, we demonstrate the dual-detectable metal/bio-organic/-GaN visible/ultraviolet photodetector with electrically different polarity based on DNA-CTMA biopolymer for ultra-light-sensing applications. The smart-light-sensing DNA-CTMA/-GaN photodiode (DG-PD) shows high-performance, efficient characteristics and charge transport mechanism under dark, halogen- and UV- illuminations. The DG-PD parameters are studied using current-voltage () and transient photocurrent techniques.
Measurements show that the DG-PD has low leakage current and a negative bias shift compared to reference diode without DNA-CTMA biopolymer. It is observed that the DG-PD shows excellent recognize photocurrent behavior like halogen-illumination photocurrent with 0.75 V and UV-exposed photocurrent with 1.02 V positive bias shifts compared to dark photocurrent. In addition, the zero-bias saturation current of halogen-illumination occurs at negative and UV-exposed occurs at positive bias sides. Further, a significant transient photocurrent responses observed in halogen- and UV- irradiation with electrically different polarity.
These behaviors show that how the DNA-CTMA on -GaN is quite effective for recognizing visible and UV lights as a dual-detectable photodiode. We find that the series resistance values from measurements for DNA-CTMA biopolymer on different substrates. The formation and charge transport mechanisms with feasible interface energy band diagrams for DG-PDs under dark, halogen- and UV- illuminations are also discussed. These results indicate that the use of DNA-CTMA biopolymer on -GaN is very promising for recognize of visible and UV photocurrents in smart-sensing future technologies.