Influences of silicon nanowire morphology on its electro‐optical properties and applications for hybrid solar cells

Abstract

In this paper, we investigate the morphology, optical, and electrical properties of silicon nanowire (SiNW) arrays and their applications on inorganic/organic hybrid solar cells. The SiNW arrays are obtained by two kinds of metal-assisted chemical etching (MacEtch) processes. One is depositing assisted metal, for example, Ag, by an electron gun evaporator before etching (BE). The other is depositing assisted Ag during the etching (DE) process. The results reveal that BE method MacEtch can produce more uniform and denser SiNW arrays, but the coverage of organic materials to SiNWs is less. In terms of optical properties, the BE method SiNW arrays have higher reflectance than the DE method ones, except the wire length less than 1 mm in the wavelength range less than 500 nm. Regarding the electrical property, the minority-carrier lifetime is higher for the DE method SiNW arrays because of less surface area of SiNWs. Therefore, the best cell performance happens on the DE method SiNW/organic hybrid solar cell with wire length less than 1 mm. The short-circuit current density (J sc ) is 28.55 mA/cm 2 , open-circuit voltage (V oc ) is 0.524 V, and power conversion efficiency (PCE) is 9.56%.

An effective way to simultaneous realization of excellent optical and electrical performance in large‐scale Si nano/microstructures

“…Obviously, the reflectance is greatly suppressed through the entire spectra compared with that of the pyramid-textured surface, and the anti-reflection performance is even better for longer SiNWs. Actually, the reflectance in short wavelength range 300-600 nm shows much more significant improvement than that in long wavelength 900-1100 nm, which can be attributed to the fact that the sizes of the SiNWs are comparable with the short wavelengths [25]. Next, we turn to illustrate the anti-reflection effect of the Al 2 O 3 -coated Si N/M-Strus through the reflectance spectra of series D with different ALD cycles as shown in Figure 2(c).…”

“…Unfortunately, despite the excellent optical advantages, the SiNWsbased solar cells show yet unsatisfied energy conversion efficiencies (η) because of the serious surface recombination arising from the concomitant high surface-volume ration. Many research groups have carried out many beneficial tries to minimize the optical and electrical losses and have indeed made great progresses in the performance of SiNWs-based solar cells [12][13][14][15][16][17][18][19][20][21][22][23][24][25]. Oh et al [26] have reported an 18.2% efficient nanostructure black Si solar cell through controlling the front surface area and Auger recombination.…”

Silicon nanowire/organic hybrid solar cells with zonyl fluorosurfactanct treated PEDOT:PSS

“…To overcome this problem, Shiu et al form vertical silicon nanowire (SiNW) arrays on Si wafer to decrease the reflectance and increase the absorptance by high light-trapping effect of NW structures [7]. To date, the SiNWI poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) hybrid solar cells reach the high efficiency of � 10% [8]. However, this efficiency is still not competitive with inorganic Si solar cells [9].…”

One-step-MACE nano/microstructures for high-efficient large-size multicrystalline Si solar cells

“…However, the optical advantage of Si nanostructures has not been facile to be fully converted into the η-gain of solar cells [4][5][6][7][8][9][10][11][12][13][14][15], which is mainly ascribed to the poor electrical properties, i.e., high recombination on the surface and in the bulk of Si nanostructures. Over the past several years, substantial progresses in improvement of the electric performance have been made by carrying out various process methods such as the surface passivation [16][17][18][19][20], properly increasing sheet resistance [21,22] and optimization of morphology of mc-Si nanostructures [11,13,14,19]. Using the optimized textured structure, Zhong et al, [23] and Xiao et al, [24] have reported ηs of 15.99% and 17.46% for mc-Si nanostructures based solar cells with the standard solar wafer size of 156 Â 156 mm 2 through reactive ion etching (RIE), respectively.…”