Surfactant-assisted synthesis of semiconductor hybrid Cd/Hg-selenidostannates with enhanced optoelectronic and piezoelectric properties†

Abstract

Multifunctional compounds have attracted significant attention due to their wide-ranging applications in advanced technologies. In this study, we synthesized two semiconductor hybrid Cd/Hg-selenidostannates, (H₂BPP)₂CdSn₃Se₉ and (H₂DMP)₂Hg₄Sn₄Se₁₅, employing 1,3-bis(4-piperidinyl) propane and 1,5-diamino-2-methylpentane through a surfactant-assisted thermal method. Remarkably, these hybrid chalcogenides are highly soluble in DMF, facilitating the formation of smooth, pinhole-free thin films via a spin-coating method. (H₂BPP)₂CdSn₃Se₉ and (H₂DMP)₂Hg₄Sn₄Se₁₅ films exhibit exceptional stability under high humidity and heat, with semiconducting band gaps of 2.12 eV and 2.21 eV, respectively. These band gaps enable strong light absorption and charge carrier generation, which directly contribute to their significant photocurrent responses. Specifically, photocurrent measurements show I_light values of 1.5 μA cm⁻² and 1 μA cm⁻² at 0.8 V for (H₂BPP)₂CdSn₃Se₉ and (H₂DMP)₂Hg₄Sn₄Se₁₅, notably higher than the 0.30 μA cm⁻² observed for the commercially available SnSe₂ electrode under the same conditions. Building on these interesting electrical properties, (H₂BPP)₂CdSn₃Se₉ also showed notable piezoelectric properties, resulting from its unique structural framework that supports both efficient charge transport and mechanical responsiveness. These promising stability and multifunctional characteristics highlight the potential of these hybrid selenidostannates for advanced optoelectronic and piezoelectric applications.