Organic phototransistors (OPTs) hold significant promise for cost-effective, flexible optoelectronic applications, particularly in Shortwave-Infrared (SWIR) detection, which is crucial for applications such as health monitoring, communications, and artificial vision. Traditional OPTs often rely on unipolar materials, limiting their efficiency by utilizing only one type of charge carrier. In contrast, ambipolar organic semiconductors (OSCs), transporting both electrons and holes, can fully harness photogenerated carriers, thereby enhancing device performance. Here, high-performance, solution-processed ambipolar single-component SWIR OPTs are demonstrated by fine-tuning the number of fused thiophene rings in donor–acceptor (D–A) conjugated polymers utilizing thiadiazoloquinoxaline-unit (TQ) as the electron-deficient unit. Through systematic polymer characterizations and optoelectronic device characterizations it was revealed that three fused thiophene rings (TQ-T3) delivered ambipolar NIR phototransistors with well-balanced hole and electron mobilities of 0.03 and 0.02 cm² V⁻¹ s⁻¹ and the highest reported specific detectivity of 2 × 10⁸ Jones (at 1100 nm), with external quantum efficiency of 1400% and 1200% for the p-type and n-type single-component active layer material, respectively. These findings contribute to advancing the design of efficient ambipolar OPTs for SWIR detection, with potential applications in imaging and sensing technologies.

Silver selenide (Ag₂Se) is a promising thermoelectric material for near-room-temperature applications, yet its scalable fabrication remains challenging due to limitations in conventional synthesis routes and the strong dependence of its properties on processing conditions. In this work, the pack cementation technique is introduced as a novel cost-effective, and industrially viable route for producing β-Ag₂Se powders. The influence of synthesis parameters on phase formation, composition, and microstructure is examined, and their correlation with thermoelectric behavior is studied to establish clear structure–property relationships. The resulting Ag₂Se is comprehensively evaluated for quality and performance. Phase-pure orthorhombic β-Ag₂Se with near-stoichiometric composition and a uniform microstructure was successfully synthesized, with phase purity preserved after consolidation without secondary phases. The material exhibited competitive thermoelectric performance, achieving a maximum ZT = 0.63 at 352 K and stable operation up to ~375 K. These findings demonstrate that pack cementation can deliver high-quality Ag₂Se with competitive efficiency, highlighting its potential for future optimization and large-scale production.

We investigate the electrical transport and low-frequency noise (LFN) characteristics of hydrothermally grown n-type ZnO nanorod/nanotextured film homojunctions synthesized via chemical bath deposition with varying Lithium nitrate concentrations. Homojunctions fabricated without Lithium nitrate or with moderate concentrations exhibit stable rectifying behavior, whereas very low or high lithium nitrate levels induce contact-dominated noise or defect-induced instability. Current–voltage analysis reveals asymmetric space-charge-limited current (SCLC) transport: reverse-bias conduction is governed by trap-free SCLC in nanorods, enabling electron mobility extraction, while forward-bias transport is dominated by trap-controlled SCLC in the nanotextured film, consistent with an exponential trap-state distribution. LFN studies show that forward-bias 1/f noise originates from trapping–detrapping in the nanotextured film, whereas reverse-bias noise follows Hooge's mobility fluctuation model. Noise variations with lithium nitrate concentration correlate with changes in trap-state distributions. Overall, this work demonstrates that electrical characterization combined with LFN analysis offers a sensitive and reliable approach for probing defect-mediated electronic disorder in chemically grown oxide semiconductors.