Das Priyanka, Saha Satyajit, Bhunia Amit Kumar
Department of Physics, Vidyasagar University, Paschim, Medinipur 721102, India.
Department of Physics, Government General Degree College Gopiballavpur-II, Jhargram 721517, India.
ACS Omega. 2024 Dec 26;10(1):294-305. doi: 10.1021/acsomega.4c06008. eCollection 2025 Jan 14.
Effective engineering of nanostructured materials provides a scope to explore the underlying photoelectric phenomenon completely. A simple cost-effective chemical reduction route is taken to grow nanoparticles of Cd Zn S with varying = 1, 0.7, 0.5, 0.3, and 0. X-ray diffraction confirms the formation of different phases of targeted Cd Zn S, while field emission scanning electron microscopy shows change of nanostructures. Energy-dispersive X-ray spectroscopy determines the composition of the grown nanostructures as CdS, CdZnS, CdZnS, CdZnS, and ZnS. The optical absorption study determines the band gap shift with change of composition as well as with quantum confinement. The fluorescence lifetime for each nanomaterial is determined by time-correlated single photon counting, and Raman analysis revealed that ZnS exhibits the highest blue shift. Thus, there is a possibility to apply such grown nanomaterials for fabrication of heterojunction-based photodetectors (PDs) in a broad wavelength region. Cd Zn S nanostructures on n-type bulk silicon (Si) were successfully fabricated by a simple cost-effective spin coating method and present hybrid heterojunction PDs. The fabricated p-n heterojunction exhibits good rectifying behavior at room temperature under a reverse bias condition. Also, it was observed that the heterojunction is extremely sensitive to the irradiation of visible light because of the significant optoelectric effect with a good / ratio (here, is the current in the presence of light and is the dark current), quick response time (40 to 1005 ms), and good reproducibility (three cycles of / for each sample are observed). It was observed that the responsivity value gradually decreases for = 1 to = 0 in the Cd Zn S/n-Si heterojunction, i.e., it is maximum for CdS NRs (6.74 × 10 mA/W), intermediate for CdZnS NPs (4.49 × 10 mA/W), and minimum for ZnS NPs (2.72161 × 10 mA/W). A similar nature has been observed in the case of detectivity, and hence it is a maximum (1.45 × 10 Jones) for CdS NRs. The photocurrent generation at the heterojunction showed excellent "on" and "off" switching behavior in the presence and absence of light illumination. Response time and gain change significantly with change of composition. The responsivity and detectivity with good photoresponse originated from the realization of special microstructures, enhancing the photoelectric behavior of Cd Zn S materials for applications in low-dimensional PDs covering a large wavelength region.
纳米结构材料的有效工程设计为全面探索潜在的光电现象提供了空间。采用一种简单且经济高效的化学还原路线来生长不同摩尔分数（x = 1、0.7、0.5、0.3和0）的CdₓZn₁₋ₓS纳米颗粒。X射线衍射证实了目标CdₓZn₁₋ₓS不同相的形成，而场发射扫描电子显微镜显示了纳米结构的变化。能量色散X射线光谱确定了生长的纳米结构的组成分别为CdS、CdZnS、CdZnS、CdZnS和ZnS。光学吸收研究确定了带隙随组成变化以及量子限制的变化情况。通过时间相关单光子计数确定了每种纳米材料的荧光寿命，拉曼分析表明ZnS表现出最大的蓝移。因此，有可能将这种生长的纳米材料应用于在宽波长区域制造基于异质结的光电探测器（PD）。通过一种简单且经济高效的旋涂方法成功地在n型块状硅（Si）上制备了CdₓZn₁₋ₓS纳米结构，并展示了混合异质结光电探测器。制备的p - n异质结在室温下反向偏置条件下表现出良好的整流行为。此外，观察到由于显著的光电效应以及良好的光电流与暗电流比值（这里，Iₗ是光照下的电流，I₀是暗电流）、快速响应时间（40至1005毫秒）和良好的可重复性（每个样品观察到Iₗ/I₀的三个循环），异质结对可见光照射极其敏感。观察到在CdₓZn₁₋ₓS/n - Si异质结中，从x = 1到x = 0，响应度值逐渐降低，即对于CdS纳米棒最大（6.74×10⁻² mA/W），对于CdZnS纳米颗粒居中（4.49×10⁻² mA/W），对于ZnS纳米颗粒最小（2.72161×10⁻² mA/W）。在探测率方面也观察到类似的性质，因此对于CdS纳米棒探测率最大（1.45×10¹¹ Jones）。异质结处的光电流产生在有光和无光照射下表现出优异的“开”和“关”切换行为。响应时间和增益随组成变化而显著变化。具有良好光响应的响应度和探测率源于特殊微观结构的实现，增强了CdₓZn₁₋ₓS材料在覆盖大波长区域的低维光电探测器中的光电行为。
