Semiconducting nanomaterials synthesized using wet chemical techniques play an important role in emerging optoelectronic and photonic technologies. Controlling the surface chemistry of the nano building blocks and their interfaces with ligands is one of the outstanding challenges for the rational design of these systems. We present an integrated theoretical and experimental approach to characterize, at the atomistic level, buried interfaces in solids of InAs nanoparticles capped with Sn₂S₆^4– ligands. These prototypical nanocomposites are known for their promising transport properties and unusual negative photoconductivity. We found that inorganic ligands dissociate on InAs to form a surface passivation layer. A nanocomposite with unique electronic and transport properties is formed, that exhibits type II heterojunctions favourable for exciton dissociation. We identified how the matrix density, sulfur content and specific defects may be designed to attain desirable electronic and transport properties, and we explain the origin of the measured negative photoconductivity of the nanocrystalline solids.

使用湿化学技术合成的半导体纳米材料在新兴的光电和光子技术中起着重要作用。控制纳米结构单元的表面化学以及它们与配体的界面是合理设计这些系统的重大挑战之一。我们提供了一种综合的理论和实验方法，用于在原子水平上表征被Sn ₂ S ₆ ^4–覆盖的InAs纳米颗粒的固体中的掩埋界面配体。这些原型纳米复合材料以其有前途的传输性能和不寻常的负光电导性而闻名。我们发现无机配体在InAs上解离形成表面钝化层。形成具有独特电子和传输性质的纳米复合材料，其表现出有利于激子离解的II型异质结。我们确定了可以如何设计基质密度，硫含量和特定缺陷，以获得所需的电子和传输性能，并且我们解释了纳米晶固体的负光电导率的测量来源。