Abstract
Vertical silicon nanowire (Si NW) arrays on a Si (100) substrate have been prepared by using a low‐cost and facile Ag‐assisted chemical etching technique. The reflectance of Si NW arrays is very low (<1%) in the spectral range from 400 to 1000 nm. By phosphorus diffusion into Si NW arrays to fabricate solar cells, the power conversion efficiency of 8.84% has been achieved. This power conversion efficiency is much higher than that of the planar cell with the similar celling technology. It is found that the efficiency of Si NW solar cells is intimately associated with their excellent antireflection property. The surface recombination of Si NWs is the main obstacle for the improvement of solar cell efficiency. The current results are helpful to the advancement of the application of Si NWs in photovoltaics.
Highlights
Silicon nanowires (Si NWs) have attracted much attention for photovoltaic applications because of their unique optical and electrical properties compared to bulk silicon [1,2,3,4]
All these results show that despite the excellent AR property of silicon nanowire (Si NW), the efficiency of solar cells based on Si NWs is much lower than that of conventional silicon solar cells
The scanning electron microscope (SEM) observation clearly revealed that the lengths of the produced Si NWs increased with the etching time, ranging from 340 nm to 1700 nm, Figure 1: Schematic illustration of the fabrication process for preparing Si NW arrays-based solar cells. (a) Initial p-type silicon wafer. (b) Formation of Vertical Si NW arrays on the wafer. (c) Formation of a spatially uniform n-type emitter by phosphorus diffusion. (d) Formation of electrode on the rear and front surfaces. (e) Planar schematic of the device
Summary
Silicon nanowires (Si NWs) have attracted much attention for photovoltaic applications because of their unique optical and electrical properties compared to bulk silicon [1,2,3,4]. Zhu’s group fabricated Si NW solar cells based on single-crystal Si substrate and polycrystalline Si substrate They obtained the power conversion efficiency (η) of 9.31% and 4.73% [8]. Using a PSG-doped Si NW arrays as the n+ emitters and a screen-printing technique to fabricate front electrodes, the efficiency of Si NW solar cells has fallen in the range from 3.55% to 16% [12]. All these results show that despite the excellent AR property of Si NWs, the efficiency of solar cells based on Si NWs is much lower than that of conventional silicon solar cells.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have