Design of Silicon Nanowire Array for PEDOT:PSS-Silicon Nanowire-Based Hybrid Solar Cell

Among various photovoltaic devices, the poly 3, 4-ethylenedioxythiophene:poly styrenesulfonate (PEDOT:PSS) and silicon nanowire (SiNW)-based hybrid solar cell is getting momentum for the next generation solar cell. Although, the power-conversion efficiency of the PEDOT:PSS–SiNW hybrid solar cell has already been reported above 13% by many researchers, it is still at a primitive stage and requires comprehensive research and developments. When SiNWs interact with conjugate polymer PEDOT:PSS, the various aspects of SiNW array are required to optimize for high efficiency hybrid solar cell. Therefore, the designing of silicon nanowire (SiNW) array is a crucial aspect for an efficient PEDOT:PSS–SiNW hybrid solar cell, where PEDOT:PSS plays a role as a conductor with an transparent optical window just-like as metal-semiconductor Schottky solar cell. This short review mainly focuses on the current research trends for the general, electrical, optical and photovoltaic design issues associated with SiNW array for PEDOT:PSS–SiNW hybrid solar cells. The foremost features including the morphology, surface traps, doping of SiNW, which limit the efficiency of the PEDOT:PSS–SiNW hybrid solar cell, will be addressed and reviewed. Finally, the SiNW design issues for boosting up the fill-factor, short-circuit current and open-circuit voltage will be highlighted and discussed.

A Silicon Nanowire Array Biosensor Fabricated by Complementary Metal Oxide Semiconductor Technique for Highly Sensitive and Selective Detection of Serum Carcinoembryonic Antigen

In this paper, we present a highly sensitive and selective detection of serum carcinoembryonic antigen (CEA) based on silicon nanowire (SiNW) array device. With the help of traditional microfabrication technology, low-cost and highly controllable SiNW array devices were fabricated. After a series of surface modification processes, SiNW array biosensors show rapid and reliable response to CEA; the detection limit of serum CEA was 10 fg/mL, the current signal is linear with the logarithm of serum CEA concentration in the range of 10 fg/mL to 100 pg/mL. In this work, SiNW array biosensors can obtain strong signal and high signal-to-noise ratio; these advantages can reduce the production cost of the SiNW-based system and promote the application of SiNWs in the field of tumor marker detection.

Fabrication of a Silicon Nanowire Solar Cell on a Silicon-on-Insulator Substrate

This study proposes metal-assisted chemical etching (MAE) as a facile method to fabricate silicon nanowire (SiNW) array structures, with high optical confinement for thin crystalline silicon solar cells. Conventional SiNW arrays are generally fabricated on Si wafer substrates. However, tests on conventional SiNW-based solar cells cannot determine whether the photo-current is derived from SiNWs or from the Si wafer. Herein, SiNW arrays were fabricated on a silicon-on-insulator substrate with a 10-μm-thick silicon layer for measuring the photocurrent of the SiNW only. The 9 μm-long p-type SiNW arrays were applied to a solar cell structure fabricated using an n-type H-doped amorphous Si layer, thereby confirming the photovoltaic effect. However, the device exhibited a conversion efficiency of 0.0017% because of a low short-circuit current (Jsc) and a low open-circuit voltage (Voc). The low Jsc resulted from a high series resistance and high absorption loss from the amorphous Si layer, whereas the low Voc resulted from the high surface recombination velocity of the SiNW array structure. Therefore, reducing the surface recombination of SiNW-based solar cells can improve their conversion efficiency.

Core–shell silicon nanowire array–Cu nanofilm Schottky junction for a sensitive self-powered near-infrared photodetector

A sensitive self-powered near infrared light photodetector was fabricated by coating a freestanding silicon nanowire (SiNW) array with a layer of Cu nanofilm.

Radial p-n Junction Solar Cells by Core-Shell Silicon Nanowire Arrays

ABSTRACTWe first fabricated a p-type single-crystalline SiNW array as the core by statistic electroless metal deposition (SEMD) method[1]. This structure exhibits per excellent absorption efficiency without increasing the diffusion path, indicating 1.75 times greater performance than Si-based planar solar cells under the same condition[2]. Next, we employed a method of spin-on dopant (SOD) to fabricate an n-type layer as an external thin shell, which benefits to decouple the absorption of light from charge transport by allowing lateral diffusion of minority carriers to the p-n junction rather than many microns away as in Si bulk solar cells, and is suitable for our SiNW array with a hydrophilic surface. Finally, our SiNW-based solar cell possesses strong broadband absorption and low reflection from visible light to near IR, in which the highly light trapping mechanism stems from the effective medium theory (EMT) to demonstrate only less than 3% of total reflectance in the range of 500-1100 nm. It also shows conversion efficiency improvement of 20% compared with the planar single-crystalline Si solar cell by the same fabrication processes. The proposed novel photovoltaic device by our core-shell SiNW array revolutionizes the current architecture of solar cells, promising niche points of (1) better absorption, (2) self-antireflection, and (3) low-cost process.