Novel energy efficient window coatings based on In doped CuS nanocrystals with enhanced NIR shielding performance

To achieve good indoor thermal comfortability in the hot summer days, searching for suitable solar shielding materials for buildings is of great importance. In this work, In doped CuS nanocrystals were first synthesized as novel NIR shielding materials for energy efficient windows. The influence of In doping on the microstructure, phase composition, optical performance, and thermal property of CuS were systematically explored. All the products adopted a hexagonal structure. Both of CuS and In doped CuS nanocrystals were composed of nanoplates and nanorods. All samples showed high visible transmittance (63.9-78.4%). Optical tests confirmed that the doping of indium ions was an effective way to improve the NIR shielding performance of the CuS films. The NIR shielding value of the films increased from 47.2% to 68.2% when the doping amount of In increased from 0 to 2%. The reason can be attributed to the enhanced NIR absorption induced by the increased hole concentration after doping of In3+ ions. Moreover, the In doped CuS films lowered the indoor temperature of the heat box by 8.4 degrees C in the thermal tests, further confirming the superior NIR shielding performance of In doped CuS nanocrystals.

Automated summary

In doped CuS nanocrystals were synthesized and demonstrated excellent NIR shielding performance and high visible transmittance as solar shading materials. The doping of indium ions effectively enhanced the NIR shielding effect of CuS films, leading to a significant indoor temperature reduction of 8.4 degrees Celsius.