LAUSR

We demonstrate a low-concentrated solar-pumped laser (SPL) with natural sunlight by using an all-inorganic cesium lead halide perovskite (CsPbBrxI3−x) nanocrystal (NC) dispersed in toluene as a sensitizer. The perovskite NCs exhibit substantial advantages for SPL applications because of their broad absorption and narrow photoluminescence (PL) spectra with high quantum yield using inexpensive commercial precursors. We successfully synthesized CsPbBrxI3−x NCs with precisely tuned PL wavelengths from 581 to 612 nm by altering the I/Br ratio to achieve spectral overlap with Nd3+ ions, which have been widely used as a laser medium for SPLs. The measurement results show that the laser output power is highly sensitive to the peak PL wavelength of the NCs, and the highest laser output was obtained at the peak wavelength of 595 nm. Although the synthesized NCs have a wider absorption band, the laser output power obtained was much less than that of an organic dye of rhodamine 6G (R6G). The numerical analyses show that the optimal peak PL wavelength is 10 nm shorter than the absorption peak of Nd3+ ions because of the reflection property of the dichroic mirror coated on the input window. Moreover, we found that the concentration of NCs needs to be optimized in response to the peak PL wavelength. The calculations show that a laser output power 2.7 times greater than that of R6G can be obtained under an optimal peak PL wavelength of 575 nm and a concentration of 24 g/l for the CsPbBrxI3−x NCs.