The compounding strategy can effectively adjust certain properties of the host perovskite materials, such as carrier transport properties, luminescence properties, light absorption properties, etc. It is a flexible and uncomplicated method to broaden the response band of the perovskite material for vis-NIR (near infrared) band phtodetection.

In a study published in Advanced Optical Materials, a research group led by Prof. YU Weili from Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP) of the Chinese Academy of Sciences (CAS) proposed a laser assisted inversed temperature crystallization (LA-ITC) method and synthesized the Ag₂S-quantum-dots-in-perovskite (Ag₂S-QDiP) matrix, which owed photoelectric response in both vis (532 nm) and NIR (1064 nm) band.

Interestingly, researchers used a 1064 nm CW laser as an energy source to provide the required temperature for inverse temperature crystallization. In addition, the synthesis device was ingeniously designed combining the space limitation method. A SiO₂/Si substrate was inserted into a 10 mm × 10 mm × 30 mm quartz growth cell. The perovskite precursor solution was filled the limited space between the substrate and the front wall of the growth cell through capillary action. The laser was directly irradiated on the substrate without focusing. It took about 40 minutes to grow a Ag₂S-QDiP matrix of 1 mm × 1 mm × 20 μm. Ag₂S-QDiP matrixes with a thickness of micrometer to ten micrometers can be synthesized. In addition, the synthesized Ag2S-QDiP matrixes have broad absorption characteristics in the vis-NIR band, which benefits for applications in high-peformance broad band photodetectors as a photoactive layer.

Then, a horizontal structure photodetector was prepared based on the Ag₂S-QDiP matrix. 80 nm gold electrode was deposited on the crystal surface by thermal evaporation method. The electrode spacing was 100 μm. The designed and manufactured Ag₂S-QDiP-enabled photodetector exhibited considerable broad-band responsivity and detectivity of 1.17 A W^-1 and 6.24 × 10¹⁴ Jones under 532 nm, and 57.69 mA W^-1 and 1.03 × 10¹¹ Jones under 1064 nm, respectively.

This work highlights the compounding strategy as an efficient method for tuning the inherent properties of perovskite materials and for developing more universialy applicable material system.