Lead-free perovskites are promising for photodetector applications due to their excellent optoelectronic properties and low toxicity. However, the performance of perovskite-based photodetectors is often limited by defects in the films, leading to non-radiative recombination and reducing carrier mobility. In this work, we report the significant performance enhancement of CsBi₃I₁₀ perovskite photodetectors through Mn doping. Mn-doped CsBi₃I₁₀ films were prepared in an air environment, which still shows good stability. Structural and photoelectronic characterizations confirm that Mn doping effectively passivates defects, suppresses non-radiative recombination, and reduces the dark current. Furthermore, this doping strategy leads to a remarkably weak light detection feature and high reproducibility of the photodetectors. The optimized device achieves a responsivity of 1.11 A/W, a specific detectivity of 1.62 × 10¹² Jones, a fast response time of 4.53 (rise) and 1.47 μs (decay) under 650 nm illumination. Considering its special response spectrum and fast response under low-light conditions, a blood oxygen saturation monitoring system was successfully built on the Mn-doped CsBi₃I₁₀ perovskite, achieving high sensitivity. This work not only demonstrates an effective doping strategy for improving the performance of lead-free perovskite photodetectors but also highlights their potential as low-toxicity candidates for wearable health monitoring.

Miniaturized optical wavelength-sensing devices based on solution-processed organic materials hold great promise for integration into portable and wearable technologies. Yet, the realization of self-powered compact wavelength sensors remains elusive. Here, we report a self-powered wavelength sensor built from broadband photodetectors featuring a meticulously engineered PM6:L8-BO active layer. By systematically varying the donor–acceptor stoichiometries and implementing these blends in nano-scale active layers (50 and 100 nm) that modulate the internal optical field distribution, we tailor the spectral responsivity of individual sensor units, yielding distinct wavelength-dependent optoelectronic signatures. An array of these wavelength-discriminating units enables quantitative discrimination and identification of incident light wavelengths. The device accurately resolves wavelengths from 380 to 850 nm with a resolution better than ~ 1 nm, determined through the photocurrent ratio mapping of the four photodetector elements. As a proof of concept, we demonstrate the device’s capability in wavelength recognition and full-color imaging, underscoring its potential for compact, self-powered, and versatile optical sensing platforms.

Colloidal indium phosphide (InP) quantum dots (QDs) have emerged as promising cadmium-free alternatives due to their tunable emission and compliance with environmental regulations. This study presents a strategy in synthesizing aminophosphine-based high-efficiency green-emissive InP QDs through precisely controlled in-situ etching and interfacial engineering. By employing ZnF₂ as an etchant during both nucleation and shelling stages, atomic-level defect passivation is achieved in magic-sized InP clusters while preserving crystallographic integrity. The synergistic integration of tri-n-octylphosphine ligands during nucleation and ZnSe interfacial layers in ZnSeS/ZnS shell growth effectively suppressed the occurrence of excessive etching, yielding green-emission QDs with exceptional photoluminescence quantum yield (93%) and narrow emission linewidth (36 nm). Advanced surface modification using carboxylic acid–thiol bifunctional ligands further enhanced charge transport properties. Prototype quantum dot light-emitting diodes fabricated from these optimized QDs demonstrated performance in InP-based devices, achieving the maximum external quantum efficiency of 4.6% and a peak maximum luminance exceeding 13,000 cd/m². The etching–optical properties–surface passivation interdependence in InP QDs was investigated by femtosecond transient absorption spectra. This work establishes a universal framework for balancing oxide removal efficiency and core dissolution in InP QDs. The developed approach offers practical solutions to long-standing challenges in controlling defects during InP QD synthesis.

For the new display technology based on quantum dots (QDs), realizing high-precision arrays of red, green, and blue (RGB) pixels has been a significant research focus at present, aimed at achieving high-quality and high-resolution image displays. However, challenges such as material stability and the variability of process environments complicate the assurance of quality in high-precision patterns. The novel optical patterning technology, exemplified by direct photolithography, is considered a highly promising approach for achieving submicron-level, hyperfine patterning. On the technological level, this method produces patterned quantum dot light-emitting films through a photochemical reaction. Here, we provide a comprehensive review of various methods of QD photolithography patterning, including traditional photolithography, lift off, and direct photolithography, which mainly focused on direct photolithography. This review covers the classification of direct photolithography technologies, summarizes the latest research progress, and discusses future perspectives on the advancement of photolithography technology de-masking.