Synthesis of Bi2S3 by MOCVDThursday (24.09.2020) 17:35 - 17:50 Z: Special Symposia I Part of:
Bismuth chalcogenides are well-known as promising future materials to address the growing demand on efficient, renewable and innovative energy conversion technologies. The combination of bismuth and sulfur Bi2S3, both non-toxic and earth-abundant elements, is known to have high potential as absorber material in photovoltaics and for the electrocatalytic oxidation of water.
One of today’s main challenges is the development of synthetic strategies towards these materials in the reliable and reproducible high quality required for device implementation. For this purpose, the ( chemical vapor deposition) CVD approach in combination with the single-source concept can provide an efficient and atom economic pathway .
Suitable molecular compounds containing the elements bismuth and sulfur that fulfill the requirements as single-source precursors are crucial factors for successfully obtaining the high purity and homogeneity in the later material, that can be achieved from gas-phase deposition methods, such as CVD. The available molecular precursors for Bi2S3 so far suffer mainly from low volatility or complex decomposition behavior, making it difficult to exploit the full potential of the CVD process. In this talk, we present a new molecular single-source precursor with high volatility and a well-defined decomposition to Bi2S3. Additionally, we exemplify how small changes on the molecular level can alter the result of the CVD process, obtaining a completely different phase, and reveal the driving forces on the atomic scale with the support of DFT calculations. Especially in the field of two-dimensional materials the ability to control the crystallographic orientation of the material on a certain substrate is highly desirable and may often be a decisive criterion for the applicability in a certain device architecture. We will present here examples for highly oriented Bi2S3 structures that grow uniformly and with homogeneous size distribution from CVD of a molecular single-source precursor.