(167b) Lead-Free, Hybrid, Organic-Inorganic Halide for Light Harvesting

We will present the synthesis and optoelectronic properties of a lead-free, organic inorganic halide structures and show their integration as light harvesters in solar cells. Organic inorganic lead halide perovskite based solar cells have gained attention as a promising contender with nearly 20 % power conversion efficiencies. However, the environmental liabilities with the use and disposal of lead has led to the development of several non-lead based hybrid halides. The natural choice of many researchers has been tin (Group 14 , period 5) and to some extent bismuth (group 15, period 6). Although relatively new, the instability of tinâ??s 2+ oxidation state has been a concern in spite of good semiconducting behavior. Here we will report the successful synthesis of a Ti based semiconductor with tunable bandgap based on the choice of the organic moiety. We will present and discuss the optical characteristics (ranging from 1.5 to 2.06) as well as the I-V characteristics of the of the various structures. While some of the synthesized products were clearly perovskites (based on XRD data), there are couple of structures whose crystalline structures have not yet been identified. The authors believe the XRD patterns to be a result of layered structures and expect to have it deciphered to present. The response of solar cell containing the hybrid halides coated onto a TiO₂ or ZnO will be presented.