Three-Dimensional a-Si:H Solar Cells on Glass Nanocone Arrays Patterned by Self-Assembled Sn Nanospheres

Abstract

We introduce a cost-effective method of forming size-tunable arrays of nanocones to act as a three-dimensional (3D) substrate for hydrogenated amorphous silicon (a-Si:H) solar cells. The method is based on self-assembled tin nanospheres with sizes in the range of 20 nm to 1.2 μm. By depositing these spheres on glass substrates and using them as an etch mask, we demonstrate the formation of glass nanopillars or nanocones, depending on process conditions. After deposition of 150 nm thick a-Si:H solar cell p-i-n stacks on the glass nanocones, we show an output efficiency of 7.6% with a record fill factor of ~69% for a nanopillar-based 3D solar cell. This represents up to 40% enhanced efficiency compared to planar solar cells and, to the best of our knowledge, is the first demonstration of nanostructured p-i-n a-Si:H solar cells on glass that is textured without optical lithography patterning methods.

Light management through guided-mode resonances in thin-film silicon solar cells

“…Numerous studies have been conducted to improve light-capture and collection efficiency of thin absorbing layers. The application of diffractive optics, [4][5][6] random texturing, 7,8 antireflective layers, 9,10 plasmonics, [11][12][13] photonic crystals, [14][15][16] guided-mode excitation, 6,17,18 and three-dimensional structures like nanowire, nanodome, and nanocone solar cells [19][20][21] shows distinguished improvements in solar absorption. Though each mechanism contributes to the manipulation of optical path lengths inside the films, the most efficient light-harvesting scheme is yet to be convincingly identified.…”

Effects of hydrogen pressure on hydrogenated amorphous silicon thin films prepared by low‐temperature reactive pulsed laser deposition

“…Hydrogenated amorphous silicon (a-Si:H) thin-films are being developed by several methods, including plasma-enhanced chemical vapor deposition [1,2,3], hotwire chemical vapor deposition [4,5], sputtering [6,7,8], chemical annealing [9], and reactive pulsed laser deposition (PLD) [10,11,12,13], among others, resulting in various optical and electrical properties, film qualities and uniformities, and deposition rates. Reactive pulsed laser deposition allows for the development of hydrogenated silicon thin films via laser ablation of a silicon target in a hydrogen atmosphere.…”

Accounting for localized defects in the optoelectronic design of thin-film solar cells

“…In order to achieve the high efficiencies that are required to make such technologies competitive with traditional wafer-based solar cells, it is critical to optimize both their optical and electrical performance. While thin-film silicon solar cells typically rely on randomly textured substrates to achieve light trapping [5], [6], significant attention has recently been directed toward designed nanostructuring of solar cells, which offers increased control of light absorption and propagation in the device [2], [3], [7]- [24]. Design of such structures is aided by the use of computer simulations that account for both optical and electrical performance of the device [8], [25].…”

“…Design of such structures is aided by the use of computer simulations that account for both optical and electrical performance of the device [8], [25]. Many promising nanophotonic designs involve structuring of the active layers themselves [3], [14]- [24]. Such approaches can offer enhanced light trapping through antireflection effects, resonant absorption in semiconductor nanostructures, and improved control over the optical mode structure in the active layer [3], [15].…”