Design And Optimization Of Horizontal Nanowire Solar Cells

Semiconductor nanowires are regarded as one of the ideal building blocks for a new generation of solar cells due to their unique onedimensional structure and novel optoelectronic properties.Among them,the development of nanowire array solar cells perpendicular to the substrate is becoming more and more mature in terms of theory and technology,and important breakthroughs have been made in performance.Another type of horizontal nanowire solar cells has important application potential in miniaturized optoelectronic systems and flexible wearable devices,and has become a research hotspot in recent years.Compared with vertical nanowire arrays,the development of horizontal nanowire solar cells is relatively lagging behind,and faces challenges such as poor light trapping ability and low light absorption efficiency.This paper focuses on the design of horizontal GaAs nanowire solar cells,improves the photoelectric conversion efficiency of the device through structural optimization,and initially explores its application potential as a flexible device.The main work and innovations of the paper are as follows:(1)The optoelectronic properties of horizontal GaAs nanowire solar cells were investigated.The results show that when the radius is 90 nm and the period is five radii,it has the highest photoelectric conversion efficiency of 10.8%,which is twice that of thin-film solar cells of the same thickness,but significantly lower than that of vertical nanowire array solar cells.Large transmission loss and weak light trapping ability.(2)A deep subwavelength single horizontal GaAs nanowire solar cell structure based on half-wave dipole antenna is designed.The results show that the locally enhanced electromagnetic field formed near the metal antenna can significantly improve the light-binding ability of the nanowires under the illumination of specific wavelengths of light,thereby increasing the photogenerated carrier concentration.For nano wires with a diameter of 90 nm,the conversion efficiency after placing five pairs of antennas increased from 8.78%to 12.3%.(3)A horizontal GaAs nanowire solar cell structure based on Si02/MgF2 substrate is designed.Studies have shown that the refractive index difference between air/SiO2 and SiO2/MgF2 can cause multiple reflections and absorption of incident light,thereby significantly enhancing the light absorption of nanowires over a wide spectral range.The conversion efficiency of the nanowire with a diameter of 180 nm reaches 18%,which is 7.2%higher than that of the traditional structure.(4)The optoelectronic properties of horizontal GaAs nanowire solar cells on PDMS flexible substrates were investigated.The results show that the horizontal nanowire solar cell has a high tolerance to the incident light angle and substrate curvature:when the incident angle is 50°,the conversion efficiency is only 4.6%lower than that of the vertical incident,while the thin film device under the same conditions The efficiency drops by 30.2%;when the substrate is bent by 30°,the conversion efficiency of the array with 9 nanowires is 7.4%,which is only 3.4%lower than that without bending.