Controllable patterning of hybrid silicon nanowire and nanohole arrays by laser interference lithography
Subjectssilicon nanoholes, metal-assisted chemical etching, nanofabrication, silicon nanostructures, silicon nanowires
metal-assisted chemical etching
MetadataShow full item record
AbstractMetal-assisted chemical etching (MACE) is a cost-effective method to fabricate Si nanostructures including silicon nanowires (SiNWs) and silicon nanoholes (SiNHs). However, the preparation of metallic template for MACE would require complex experimental conditions including strict cleaning process and multiple steps. Herein, superlens-enhanced laser interference lithography is applied to directly fabricate complicated metallic patterns and then MACE is used to obtain hybrid SiNW and SiNH arrays. Ag films are first deposited on Si substrates, and then a 1064 nm high power laser source is utilized to generate two-beam interference electric fields. Because Ag molecules are very sensitive to any input energy change, they tend to break up or aggregate and form different Ag patterns which have a specific energy threshold to lower its free energy. By manipulating the distribution of input electric field, complicated metallic patterns and their corresponding Si nanostructures with feature sizes that range from tens of nanometers to several micrometers are obtained.
CitationGuo X, Li S, Lei Z, Liu R, Li L, Wang L, Dong L, Peng K, Wang Z (2020) 'Controllable patterning of hybrid silicon nanowire and nanohole arrays by laser interference lithography', physica status solidi (RRL) - Rapid Research Letters, 14 (6), pp.2000024-.
Showing items related by title, author, creator and subject.
Effects of laser fluence on silicon modification by four-beam laser interferenceZhao, Le; Wang, Zuobin; Zhang, Jinjin; Yu, Miao; Li, Siwei; Li, Dayou; Yue, Yong; Changchun University of Science and Technology; University of Bedfordshire; Jiaotong-Liverpool University (American Institute of Physics Inc., 2015-12-17)This paper discusses the effects of laser fluence on silicon modification by four-beam laser interference. In this work, four-beam laser interference was used to pattern single crystal silicon wafers for the fabrication of surface structures, and the number of laser pulses was applied to the process in air. By controlling the parameters of laser irradiation, different shapes of silicon structures were fabricated. The results were obtained with the single laser fluence of 354 mJ/cm, 495 mJ/cm, and 637 mJ/cm, the pulse repetition rate of 10 Hz, the laser exposure pulses of 30, 100, and 300, the laser wavelength of 1064 nm, and the pulse duration of 7-9 ns. The effects of the heat transfer and the radiation of laser interference plasma on silicon wafer surfaces were investigated. The equations of heat flow and radiation effects of laser plasma of interfering patterns in a four-beam laser interference distribution were proposed to describe their impacts on silicon wafer surfaces. The experimental results have shown that the laser fluence has to be properly selected for the fabrication of well-defined surface structures in a four-beam laser interference process. Laser interference patterns can directly fabricate different shape structures for their corresponding applications.
Improved efficiency of microcrystalline silicon thin film solar cells with wide band-gap CdS buffer layerJabeen, Maria; Haxha, Shyqyri; Charlton, Martin D.B.; University of Bedfordshire; University of Southampton (Institute of Electrical and Electronics Engineers (IEEE), 2017-12-01)In this paper, we have reported a new structure based upon an optical simulation of maximum light trapping and management in microcrystalline silicon thin film solar cells by using multi texture schemes and introducing an n-type cadmium sulphide (CdS) buffer layer with the goal of extreme light coupling and absorption in silicon absorber layer. Photon absorption was improved by optimising the front and back texturing of transparent conductive oxide (TCO) layers and variation in buffer layer thickness. We have demonstrated that light trapping can be improved with proposed geometry of 1μm thick crystalline silicon absorber layer below a thin layer of wide band gap material. We have improved the short circuit current densities by 1.35mA/cm2 resulting in a total short circuit current of 25 mA/cm2 and conversion efficiency of 9% with the addition of CdS buffer layer and multi textures, under global AM1.5 conditions. In this study, we have used 2 Dimensional Full Vectorial Finite Element (2DFVFEM) to design and optimize the proposed light propagation in solar cell structure configuration. Our simulation results show that interface morphology of CdS layer thickness and textures with different aspect and ratios have the most prominent influence on solar cell performance in terms of both short circuit current and quantum efficiency.
Effect of pulse repetition rate on silicon wafer modification by four-beam laser interferenceZhao, Le; Wang, Zuobin; Li, Wenjun; Yu, M.; Zhang, Z; Xu, J.; Yu, Y.; Weng, Z.; Li, S; Maple, Carsten; et al. (IEEE, 2013-08)This paper discusses the effect of pulse repetition rates on silicon wafer modification by four-beam laser interference. In the work, four-beam laser interference was used to pattern single crystal silicon wafers for the fabrication of dots, and different laser pulse repetition rates were applied to the process in the air. The results were obtained from 10 laser exposure pulses with the single laser fluence of 283mJ/cm2, the pulse repetition rates were 1Hz, 5Hz and 10Hz, the laser wavelength was 1064nm and the pulse duration 7-9ns. The results have been observed using a scanning electron microscope (SEM) and optical microscope. They indicate that the laser pulse repetition rate has to be properly selected for the fabrication of the structures of dots using four-beam laser interference.