Colloidal semiconductor nanocrystals (NCs) represent a versatile and cost-effective class of nanomaterials with significant potential in the field of optoelectronics. These nanomaterials are characterized by their tunable optical and electronic properties, which can be precisely controlled through changes in size, shape, and composition. As a result, NCs have been widely explored for applications such as light-emitting diodes (LEDs), photodetectors, solar cells, and bioimaging. The ability to engineer their optical properties, particularly in the visible and infrared ranges, has made them highly attractive for next-generation technologies. Over recent years, major advancements in NC performance have been driven by improvements in synthetic chemistry, surface passivation, and optimization of device architectures, leading to enhanced quantum efficiencies and stability.

Semiconductor nanoplatelets (NPLs), a subclass of NCs, have garnered special attention due to their unique two-dimensional structure and atomically precise thickness control. Unlike spherical quantum dots, NPLs exhibit uniform thickness down to the atomic level, resulting in sharp and tunable optical transitions, minimal inhomogeneous broadening, and sub-monolayer surface roughness. These properties make NPLs ideal candidates for optoelectronic devices that require high performance and reproducibility. In particular, core/shell NPLs, where a core material is coated with a shell of a different semiconductor, have demonstrated improved stability and enhanced optical properties due to better surface passivation and confinement effects.¹

In this study, we investigate the potential of core/shell Cd_xHg_1-xSe/Zn_yCd_1-yS NPLs for advanced optoelectronic applications, specifically targeting the short-wave infrared (SWIR) spectral range. The SWIR region is crucial for a variety of applications, including telecommunications, biomedical imaging, and environmental monitoring, yet developing efficient materials for SWIR devices remains a challenge. Our work demonstrates the versatility of these core/shell NPLs in both light-emitting and light-detection devices, showcasing their dual functionality as a single material platform for LEDs and photodetectors. This dual capability simplifies the integration of these materials into multifunctional optoelectronic systems, reducing the need for separate NC syntheses for emission and detection functionalities.

By leveraging the unique properties of Cd_xHg_1-xSe/Zn_yCd_1-yS NPLs, we achieve tunable light emission and sensitive photodetection in the SWIR range, addressing key challenges in the fabrication of integrated optoelectronic systems. The ability to use the same NC material for both LEDs and photodetectors simplifies device fabrication, reduces production costs, and offers a pathway toward more compact and efficient optoelectronic devices. Our findings highlight the promising future of NPL-based materials in the development of next-generation SWIR technologies, with potential for broader applications across the optoelectronics landscape.