Broadband optical absorption enhancement of hexagonal nanoconical frustum arrays texturing for c-Si film solarcells

Effect of hexagonal nanoconical hole arrays based solar cells on the light absorption enhancement

“…It is worth noting that TM polarization has higher ultimate efficiency than TE polarization, which is consistent with the report [11] and different with the study [14] due to the different distribution between air and Si nanostructure. In comparison, the ultimate efficiency of SiHNH arrays higher than that of SiHNF arrays when the zenith angle is within 20 degrees and above 40 degrees.…”

“…More importantly low grade Si raw materials can be utilized when combining the nanostructures arrays, as light trapping and carrier collection can be decoupled [1,2], which is beneficial to lower the manufacturing cost. The enhanced light absorption of Si nanostructures arrays have been demonstrated both theoretically and experimentally, such as nanowire [3][4], nanohole [5][6][7][8][9], and nanocone [10][11][12][13][14] arrays. However, after introducing the high aspect ratio associated with silicon nanowire [3][4] and nanohole [5][6][7][8][9] arrays, conformal deposition of the transparent electrodes over the nanostructure surface for efficient photo-generated carrier collection becomes challenging, resulting in low power conversion efficiencies.…”

“…The thickness H of the underlying Si film is fixed to be 800 nm, the same as in previous report [4,7,14], for easy comparison. It is found that the adding of the SiHNH arrays to the Si thin film can significantly enhance the light absorption.…”

“…The periodic boundary conditions were adopted in x, y directions and a perfectly matched layer boundary condition was used in z direction in order to let reflected light escape from simulation volume. The detailed simulation methodology can be referred elsewhere [14][15][16][17]. The reflection and transmission were calculated firstly, and the absorption was determined by A= 1 -R -T. The direction of the incident light is determined by the azimuthal (M ) and zenith (T ) angles.…”

“…There is a maximum of 31.92% for the ultimate efficiency when D top = 900 nm, and the other parameters D bot , H and L are fixed to be 100 nm, 800 nm, and 1000 nm, respectively, which are attributed to the good balance between lower reflection in the low energy region and guide-resonances excitation in the high energy region [3,12]. In comparison, the ultimate efficiency peak (30.54%) appears at D bot = 700 nm for the silicon hexagonal nanoconical frustum (SiHNF) arrays surface texture based solar cells [14]. The ultimate efficiency of the SiHNH arrays is enhanced by 4.52% compared to SiHNF arrays.…”