Fabrication of Silicon Hierarchical Structures for Solar Cell Applications

Hierarchical silicon structures consisting of micropyramids and nanowire arrays are fabricated by two-step chemical etching processes aimed at achieving cost and time effectiveness constraints without using any expensive vacuum system or complicated lithography process. The hierarchical structures can suppress the average reflectance to as low as 4.3% from 300 to 1100 nm without causing poor minority carrier lifetimes, exhibiting excellent broadband light-harvesting abilities with minimal recombination losses, which is the key point to design high-performance nanostructured solar cells. By utilizing hierarchical structures in the practical solar cells application, the short-circuit current density (JSC) shows a significant enhancement from 21.5 to 28.7 mA/cm2, and the conversion efficiency is enhanced by a factor of 35%. Such a significant enhancement is attributed not only to the superior light harvesting achieved by hierarchical structures but also to the benefit of small electrical losses in the solar cells. Thus, the concept and technique presented in this paper open avenues for developing high-performance structure solar devices.

[1]  Chih-Hsiung Huang,et al.  Realizing high-efficiency omnidirectional n-type Si solar cells via the hierarchical architecture concept with radial junctions. , 2013, ACS nano.

[2]  M. Green,et al.  Light trapping properties of pyramidally textured surfaces , 1987 .

[3]  William R. Erwin,et al.  Improving Light Harvesting in Dye-Sensitized Solar Cells Using Hybrid Bimetallic Nanostructures , 2016 .

[4]  G. M. Morris,et al.  Analysis of antireflection-structured surfaces with continuous one-dimensional surface profiles. , 1993, Applied optics.

[5]  Zongfu Yu,et al.  Optical absorption enhancement in amorphous silicon nanowire and nanocone arrays. , 2009, Nano letters.

[6]  Rajesh Kumar,et al.  Effectiveness of anisotropic etching of silicon in aqueous alkaline solutions , 2001 .

[7]  Jr-Hau He,et al.  Periodic si nanopillar arrays fabricated by colloidal lithography and catalytic etching for broadband and omnidirectional elimination of Fresnel reflection. , 2010, Langmuir : the ACS journal of surfaces and colloids.

[8]  Yi Cui,et al.  Nanowire Solar Cells , 2011 .

[9]  Po-Kang Yang,et al.  Si Hybrid Solar Cells with 13% Efficiency via Concurrent Improvement in Optical and Electrical Properties by Employing Graphene Quantum Dots. , 2016, ACS nano.

[10]  C. K. Carniglia,et al.  Scalar Scattering Theory for Multilayer Optical Coatings , 1979 .

[11]  Nathan S Lewis,et al.  Enhanced absorption and carrier collection in Si wire arrays for photovoltaic applications. , 2010, Nature materials.

[12]  Peidong Yang,et al.  Nanowire dye-sensitized solar cells , 2005, Nature materials.

[13]  Hung-Chih Chang,et al.  Photon management in nanostructured solar cells , 2014 .

[14]  M. Grätzel,et al.  A low-cost, high-efficiency solar cell based on dye-sensitized colloidal TiO2 films , 1991, Nature.

[15]  H. Angermann,et al.  Wet-chemical passivation of Si(111)- and Si(100)-substrates , 2000 .

[16]  Jr-hau He,et al.  Toward efficient and omnidirectional n-type Si solar cells: concurrent improvement in optical and electrical characteristics by employing microscale hierarchical structures. , 2014, ACS nano.

[17]  Jr-Hau He,et al.  Antireflection effect of ZnO nanorod arrays , 2010 .

[18]  M. Green,et al.  19.8% efficient “honeycomb” textured multicrystalline and 24.4% monocrystalline silicon solar cells , 1998 .

[19]  B. Rech,et al.  Texture etched ZnO:Al coated glass substrates for silicon based thin film solar cells , 1999 .

[20]  Xianzhong Sun,et al.  Photoluminescence origins of the porous silicon nanowire arrays , 2011 .

[21]  T. Yen,et al.  Applying Silicon Nanoholes with Excellent Antireflection for Enhancing Photovoltaic Performance , 2011 .

[22]  R. Behm,et al.  Wet chemical etching of Si(100) surfaces in concentrated NH4F solution: formation of (2 × 1)H reconstructed Si(100) terraces versus (111) facetting , 1993 .

[23]  Jenny Nelson.  Organic photovoltaic films , 2002 .

[24]  Jr-hau He,et al.  An efficient broadband and omnidirectional light-harvesting scheme employing a hierarchical structure based on a ZnO nanorod/Si3N4-coated Si microgroove on 5-inch single crystalline Si solar cells. , 2012, Nanoscale.

[25]  R. Tscharner,et al.  Photovoltaic technology: the case for thin-film solar cells , 1999, Science.

[26]  C. Chung,et al.  A Study of the Synthesis, Characterization, and Kinetics of Vertical Silicon Nanowire Arrays on (001)Si Substrates , 2008 .

[27]  Jr-hau He,et al.  Periodic Si nanopillar arrays by anodic aluminum oxide template and catalytic etching for broadband and omnidirectional light harvesting. , 2012, Optics express.

[28]  Niyazi Serdar Sariciftci,et al.  Organic solar cells: An overview , 2004 .

[29]  Tianchun Ye,et al.  Influence of nanowires length on performance of crystalline silicon solar cell , 2011 .

[30]  Arnan Mitchell,et al.  Micro‐ and Nanostructured Surfaces for Selective Solar Absorption , 2015 .

[31]  Jr-Hau He,et al.  Nanowire arrays with controlled structure profiles for maximizing optical collection efficiency , 2011 .

[32]  U. Das,et al.  Effect of texturing and surface preparation on lifetime and cell performance in heterojunction silicon solar cells , 2008 .

[33]  D. Cornu,et al.  Fabrication of silicon pyramid/nanowire binary structure with superhydrophobicity , 2009 .

[34]  C. Lin,et al.  Scalar scattering model of highly textured transparent conducting oxide , 2011 .