The strength of electrostatic interactions within semiconductors strongly affects their performance in optoelectronic devices. An important target is the tuning of a material’s exciton binding energy—the energy binding an electron–hole pair through the electrostatic Coulomb force—independent of its electronic band gap. Here, we report on the doping of a family of two-dimensional hybrid perovskites, in which inorganic lead halide sheets alternate with naphthalene-based organic layers, with tetrachloro-1,2-benzoquinone (TCBQ). For four out of seven n = 1 perovskites, the incorporation of the electron-accepting TCBQ dopant into the organic sublattice containing the electron-donating naphthalene species enabled the tuning of the materials’ 1s exciton binding energy. The naphthalene–TCBQ electron donor–acceptor interactions increased the electrostatic screening of the exciton, in turn lowering its binding energy relative to the undoped perovskite—by almost 50% in one system. Structural and optical characterization showed that the inorganic lattice is not significantly perturbed even though the layer-to-layer spacing increases upon molecular dopant incorporation.

半导体内部静电相互作用的强度强烈影响其在光电设备中的性能。一个重要的目标是调节材料的激子结合能，即通过静电库仑力结合电子-空穴对的能量，而与电子带隙无关。在这里，我们报道了一个二维杂化钙钛矿的掺杂情况，其中无机卤化铅片与萘基有机层交替出现，并用四氯1,2-苯并醌（TCBQ）掺杂。对于七个n  = 1的钙钛矿中的四个，将电子接受的TCBQ掺杂剂掺入含有给电子萘物种的有机亚晶格中可以调节材料的1 s激子结合能。萘-TCBQ电子给体-受体的相互作用增加了对激子的静电筛选，从而相对于未掺杂的钙钛矿降低了激子的结合能，在一个系统中降低了近50％。结构和光学表征表明，即使分子掺杂剂引入时层间距离增加，无机晶格也不会受到显着干扰。