Micro/Nanostructures for Light Trapping in Monocrystalline Silicon Solar Cells

Abstract

Due to the ongoing depletion of fossil energy, alternative energy-sources and their respective conversion technologies have become very essential. An inexhaustible and clean energy form, which is already widely used, is solar energy. However, despite much progress in recent decades, due to the limitations of materials and manufacturing technology, the ability of solar cells to convert light into electrical energy is still not very high. Enhancing light absorption and reducing electric loss are the keys to improving the overall conversion efficiency of solar cells and reducing raw material costs. The former can be achieved by using micro/nanostructures and other surface features, while the latter can be realized by surface passivation. Researchers have developed different silicon-surface texturing methods to fabricate random or periodic micro/nanostructures on the surface of silicon wafers. Thanks to the special and efficient light-trapping effects of silicon micro/nanostructures, both full angle and wideband light absorption can be achieved. Different passivation methods and materials have also been widely studied, which helps to improve the surface recombination of photogenerated carriers caused by light trapping structure and significantly enhance the power conversion efficiency of Si solar cells. In this work, theoretical studies of enhanced light-trapping in micro/nanostructures are introduced. In addition, several advanced methods for preparing micro/nanostructures on the surface of monocrystalline silicon are discussed. These can be classified as top-down and bottom-up approaches. Furthermore, passivation methods for micro/nanostructures on the surface of monocrystalline silicon solar cells are reviewed, including chemical passivation and field-effect passivation. Finally, advantages and disadvantages of the micro/nanostructure preparation technologies, and light-trapping effects of the micro/nanostructures, which were fabricated using these manufacturing technologies were summarized. Moreover, the effects of different passivation technologies on the optical properties and electrical properties of these micro/nanostructures are studied. An outlook of expected and emerging research directions for monocrystalline silicon solar cells concludes this study.

A New Texturing Approach of a Polyimide Shielding Cover for Enhanced Light Propagation in Photovoltaic Devices

“…As a consequence, the trapping of radiations is more efficient, since their path and absorption in the materials from the device supplementary increases [51,52]. On the other hand, the generation of surface roughness not only diminishes the reflectivity but additionally meliorates the wear resistance [27]. Hence, upon the mechanical abrasion of the CBDA-pBAPS, the possibilities of incident radiation to bounce back onto the material surface are increased rather than coming out to the initial medium (air), while the radiation propagation distance is enhanced inside the polymer medium.…”

“…Another important aspect of surface texturing resides in the creation of surface roughness, which is known to diminish the light reflectivity [27]. In the case of polymers, surface roughness can be changed by chemical or physical approaches.…”

The Light-Trapping Character of Pit Arrays on the Surface of Solar Cells

“…However, compared with traditional energy resources, solar energy experiences deficiencies such as high manufacturing cost and unideal transform efficiency, which seriously limit its wide application. To improve the conversion efficiency, researchers have developed light-trapping structures for various solar cells, such as nano/micro-pyramids [1][2][3][4], nanowires [5][6][7], nanocone [8][9][10][11][12], nanosphere [13][14][15][16], and porous silicon structures [17,18]. Light-trapping structures possess broadband optical absorption abilities, which can effectively lower the loss of light caused by reflection and raise the valid length of optical paths in the active layer of solar cells [19].…”

Characteristics of Elliptical Vibration-Assisted Cutting with Variations in Tilt Angle of Elliptical Locus

“…Micro/nanostructured surfaces can provide advanced and interesting functions. A large number of applications of these functional structured surfaces in different fields, including optics [ 1 , 2 ], solar energy technology [ 3 ], and measuring systems [ 4 ], provide a challenge for accurate and efficient processing. To overcome this problem, many machining methods have been demonstrated [ 5 , 6 ].…”