Misztal Kamil, Kopaczek Jan, Kudrawiec Robert
Department of Semiconductor Materials Engineering, Wrocław University of Science and Technology, Wybrzeże Stanisława Wyspiańskiego 27, Wrocław 50-370, Poland.
Photoacoustics. 2024 Nov 13;41:100668. doi: 10.1016/j.pacs.2024.100668. eCollection 2025 Feb.
Photoacoustic spectroscopy is a powerful tool for investigating semiconductors and determining some of their basic properties. However, generating a signal that is large enough for the investigated samples is still challenging. To address this, the focus is on enhancing photoacoustic (PA) signal intensity in a non-complex way, which does not require changing any part of an experimental setup. The PA signal intensity enhancement is mainly achieved by manipulating the sample volume and its surroundings. MoS, a layered material that belongs to the van der Waals crystals was selected due to ease of exfoliation to the proper thickness. A reduction in MoS thickness from 112 to 7 µm, resulted in enhancement of the PA signal by a factor of ∼50. A simple model has been proposed to describe the results based on thermal processes. Additionally, a method to determine the energy gap in transition metal dichalcogenides from PA measurements is presented.
光声光谱法是研究半导体及其某些基本性质的有力工具。然而，为被研究样品生成足够大的信号仍然具有挑战性。为了解决这个问题，重点是以一种不复杂的方式增强光声（PA）信号强度，这不需要改变实验装置的任何部分。PA信号强度的增强主要通过控制样品体积及其周围环境来实现。由于易于剥离到合适的厚度，选择了属于范德华晶体的层状材料二硫化钼（MoS）。二硫化钼厚度从112微米减小到7微米，导致PA信号增强了约50倍。已经提出了一个基于热过程的简单模型来描述这些结果。此外，还提出了一种从PA测量中确定过渡金属二硫属化物能隙的方法。
