Halide perovskites have exceptional optoelectronic properties, but a poor understanding of the relationship between crystal dimensions, composition, and properties limits their use in integrated devices. We report a new multiplexed cantilever-free scanning probe method for synthesizing compositionally diverse and size-controlled halide perovskite nanocrystals spanning square centimeter areas. Single-particle photoluminescence studies reveal multiple independent emission modes due to defect-defined band edges with relative intensities that depend on crystal size at a fixed composition. Smaller particles, but ones with dimensions that exceed the quantum confinement regime, exhibit blue-shifted emission due to reabsorption of higher-energy modes. Six different halide perovskites have been synthesized, including a layered Ruddlesden-Popper phase, and the method has been used to prepare functional solar cells based on single nanocrystals. The ability to pattern arrays of multicolor light-emitting nanocrystals opens avenues toward the development of optoelectronic devices, including optical displays.

卤化物钙钛矿具有出色的光电性能，但是对晶体尺寸，组成和性能之间关系的了解不多，限制了它们在集成器件中的使用。我们报告了一种新的多路复用的无悬臂扫描探针方法，用于合成跨越平方厘米区域的组成多样且受尺寸控制的卤化物钙钛矿纳米晶体。单粒子光致发光研究表明，由于缺陷定义的能带边缘具有多种相对独立的发射模式，其相对强度取决于固定成分下的晶体尺寸。较小的粒子，但尺寸超出量子限制范围的粒子，由于对高能模式的重吸收而显示出蓝移发射。已合成了六种不同的卤化物钙钛矿，包括层状Ruddlesden-Popper相，并且该方法已经用于制备基于单纳米晶体的功能太阳能电池。图案化多色发光纳米晶体的阵列的能力为光电子器件（包括光学显示器）的开发开辟了道路。