Linqin Jiang

The surface morphology of porous source electrodes plays a significant role in the performance of vertical channel indium–gallium–zinc oxide thin-film transistors (VC-IGZO-TFTs). This study systematically investigates the properties of porous MXene-based source electrodes and their impact on VC-IGZO-TFTs fabricated with varying MXene concentrations. As the MXene concentration increases, both the sheet resistance and porosity of the electrodes decrease. VC-IGZO-TFTs based on a 3.0 mg/mL MXene concentration exhibit optimal electrical performance, with a threshold voltage (V_th) of 0.16 V, a subthreshold swing (SS) of 0.20 V/decade, and an on/off current ratio (I_on/I_off) of 4.90 × 10⁵. Meanwhile, the VC-IGZO-TFTs exhibit excellent electrical reliability and mechanical stability. This work provides a way to analyze the influence of sheet resistance and porosity on the performance of VC-IGZO-TFTs, offering a viable approach for enhancing device efficiency through porous MXene electrode engineering.

As the most representative and widely utilized hole transport material (HTM), spiro-OMeTAD encounters challenges including limited hole mobility, high production costs, and demanding synthesis conditions. These issues have a notable impact on the overall performance of perovskite solar cells (PSCs) based on spiro-OMeTAD and hinder its large-scale commercial application. Consequently, there exists a strong demand for high-throughput computational design of novel small-molecule HTMs (SM-HTMs) that are cost-effective, easy to synthesize, and offer excellent performance. In this study, a systematic and iterative design and development process for SM-HTMs is proposed, aiming to accelerate the discovery and application of high-performance SM-HTMs. A custom-developed molecular splicing algorithm (MSA) generated a sample space of 200,000 intermediate molecules, culminating in the creation of a comprehensive database of over 7,000 potential SM-HTM candidates. In total, six promising HTM candidates were identified through MSA, density functional theory calculations and high-throughput screening. Furthermore, three machine learning algorithms, namely random forest, gradient boosting decision tree, and extreme gradient boosting (XGBoost), were employed to construct predictive models for key material properties, including hole recombination energy, solvation free energy, maximum absorption wavelength, and hydrophobicity. Among these, the XGBoost-based model demonstrated the best overall performance. The MSA methodology combining comprehensive SM-HTM database and performance prediction models, as introduced in this study, offers a powerful and universal toolkit for the design and optimization of next-generation SM-HTMs, thereby paving the way for future advancements of PSCs.

Perovskite photodetectors (PPDs) have attracted extensive attention due to their unique material properties. However, the use of electron and hole transport layers ( ETLs and HTLs) significantly increases the complexity of design and processing and reduces the reliability of the devices. To address these issues effectively, a simple strategy of eliminating the ETLs and HTLs by employing a perovskite homojunction is proposed. In this study, we examine a numerical design of p-n homojunction-based PPD without the use of carrier transport layers (CTLs), using the Silvaco TCAD simulator. To unlock the potential of the proposed design, the effects of doping concentration, mobility, thickness, and bandgap of p-perovskite and n-perovskite on the PPD photoelectric characteristics are investigated and optimized. The simulation results illustrate that a high-performance CTL-free PPD can be achieved by forming a p-n homojunction using a thin (600 nm) lowly-doped (5 × 10¹⁴ cm⁻³) n-perovskite layer with suitable mobility (1 ∼ 10 cm² V⁻¹ s⁻¹). Under optimized conditions, our findings reveal an optimum detectivity of 7.4 × 10¹³ Jones at 750 nm, the optimum responsivity is found to be 0.42 A W⁻¹ at 675 nm and the optimum EQE is 84% at 475 nm. These results highlight the promising potential of the p-n homojunction design as a device configuration for producing high-performance and reliable commercial PPDs without any CTL.