Efficient plasmonic lasing from submicron-sized visible perovskite particle on gold substrate

Utilizing surface plasmon polaritons (SPPs) is one of the most promising ways to miniaturize lasers into subwavelength-scale. Despite its potential, it has been challenging to make a plasmonic laser having a sub-micrometer scale in all three dimensions due to large cavity loss. Here, we demonstrate single-particle lasing around 540 nm with full-submicron, cesium lead bromide perovskite (CsPbBr3) crystals atop polymer-coated gold substrates at room temperature. With a large number (~100) of devices, we systematically study the lasing action of plasmonic test and photonic control groups. The achieved smallest plasmonic laser was 0.56 μm × 0.58 μm ×0.32 μm in size, ten-fold smaller than that of our smallest photonic laser. Key elements to efficient plasmonic lasing are identified as enhanced optical gain by the Purcell effect, long carrier diffusivity, a large spontaneous emission factor, and a high group index. Our results shed light on the three-dimensional miniaturization of plasmonic lasers.