Synthesis and optical properties of novel organic–inorganic hybrid UV (R–NH3)2PbCl4 semiconductors†
We report on the synthesis and the optical properties of several novel ultraviolet (UV) semiconductors (R–NH3)2PbCl4. These semiconductors are two dimensional organic–inorganic perovskite (2DOIP) materials and have multiple quantum-well energy level structures. We systematically varied the organic components (R–NH3+), and discussed their influence on the self-organization ability, excitonic optical features, and long-term photo-stabilities of the 2DOIPs. The trends of selecting the organic groups to tailor the optical features and to improve the self-organization and long-term photo-stabilities of 2DOIPs are obtained by analyzing the experimental results. Self-organization abilities are found to be highly dependent on the interactions among the organic components. The excitonic optical properties of 2DOIPs are found to depend more on the steric structures, and less on the electronic structures and chemical properties of the organic groups (R–NH2) as long as the organic groups are optically inert. However, the long-term photo-stabilities of the (R–NH3)2PbCl4 semiconductors are highly dependent on the thermal and photo stabilities of organic components. We find a new UV semiconductor, (C6H11CH2NH3)2PbCl4 (CMPC), which has better photo-stability than the usually used (C6H5C2H4NH3)2PbCl4 (PEPC).