Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group
Journal Home About Issues in Progress Current Issue All Issues Feature Issues

Light trapping design for low band-gap polymer solar cells

Stephen Foster and Sajeev John

Open Access Open Access

Abstract

We demonstrate numerically a 2-D nanostructured design for light trapping in a low band-gap polymer solar cell. Finite element method simulations are used to study the effect of varying nanostructure periodicity, height, and shape on active layer absorption. Maintaining a constant active layer thickness of 100nm we observe an enhancement in solar absorption of almost 40% relative to a planar cell. Improvements of this magnitude enable single-junction, low-band-gap cells to achieve power conversion efficiencies of 11.2% and perform competitively with even state-of-the-art tandem cells. Our design is also shown to significantly outperform tandem cells at off-normal angles of incidence.

© 2014 Optical Society of America

Full Article  |  PDF Article
More Like This
Design of light-trapping microscale-textured surfaces for efficient organic solar cells

Kanwar S. Nalwa and Sumit Chaudhary
Opt. Express 18(5) 5168-5178 (2010)

Time domain simulation of tandem silicon solar cells with optimal textured light trapping enabled by the quadratic complex rational function

H. Chung, K-Y. Jung, X. T. Tee, and P. Bermel
Opt. Express 22(S3) A818-A832 (2014)

Light trapping efficiency of organic solar cells with large period photonic crystals

Léo Peres, Valérie Vigneras, and Sophie Fasquel
Opt. Express 22(S5) A1229-A1236 (2014)

View More...

Cited By

Optica participates in Crossref's Cited-By Linking service. Citing articles from Optica Publishing Group journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (13)
Fig. 1
Fig. 1 Diagram of the cell structure studied in this work.

Download Full Size | PDF

Fig. 2
Fig. 2 Calculated values for the imaginary part of the refractive index (k) for PDTP-DFBT:PC71BM. Obtained using absorption data from [28].

Download Full Size | PDF

Fig. 3
Fig. 3 Map of MAPD as a function of opening width w1 and bottom width w2 of the grating. Triangular-shaped gratings yield the best performance.

Download Full Size | PDF

Fig. 4
Fig. 4 MAPD for different values of h as a function of the slant factor s. A value of s = 0 corresponds to no slant, and s = 1 corresponds to a fully slanted sawtooth shape. Inset shows grating geometry for h = 1000nm and s = 0.8.

Download Full Size | PDF

Fig. 5
Fig. 5 (a) Map of MAPD as a function of the grating periodicity a and grating height h. (b) The same data expressed in terms of enhancement in MAPD relative to the reference planar cell. High aspect ratio gratings yield the largest improvement.

Download Full Size | PDF

Fig. 6
Fig. 6 MAPD for different grating periodicities as a function of equivalent thickness of the active layer. Dashed line shows planar cell MAPD as a function of active layer thickness.

Download Full Size | PDF

Fig. 7
Fig. 7 Breakdown of energy losses within the cell as a function of wavelength for a = 800nm and h = 1600nm. Active layer absorption for planar reference cell shown as dashed line.

Download Full Size | PDF

Fig. 8
Fig. 8 Map of electric field intensity |E|2 (normalized to incident intensity) and time-averaged Poynting vector for a cell with a = 800nm and h = 1600nm, for incident wavelengths of a) 600nm and b) 930nm.

Download Full Size | PDF

Fig. 9
Fig. 9 MAPD as a function of corrugation height hc for ac = a, a/2, a/3 and a/4. Results are shown for (a) a = 600nm, (b) a = 900nm and (c) a = 1200nm. Grating height is fixed at h = 800nm (see Fig. 1).

Download Full Size | PDF

Fig. 10
Fig. 10 MAPD as a function of angle of incidence for the corrugation periodicities ac = a, a/2, and a/4. Results are shown for grating periodicities of (a) 600nm, (b) 900nm and (c) 1200nm. Grating height is fixed at h = 800nm (see Fig. 1).

Download Full Size | PDF

Fig. 11
Fig. 11 (a) Enhancement in MAPD relative to planar cell as a function of grating height for select periodicities. Triangular corrugation with ac = a/4 and hc = 700nm is applied at the glass-air interface. (b) Breakdown of energy losses for cell with a = 800nm and h = 1600nm. Dashed line shows active layer absorption for planar reference cell.

Download Full Size | PDF

Fig. 12
Fig. 12 (a) MAPD for a cell with a conformal Ag layer and air beneath the cell, as a function of Ag layer thickness (a = 800nm, h = 1600nm). (b) Percentage enhancement in MAPD for nanostructured cell (a = 800nm, h = 1600nm) relative to planar cell, as a function of active layer refractive index (n). The imaginary part of the index (k) is recomputed for each value of n using the procedure described in Sec. 2.

Download Full Size | PDF

Fig. 13
Fig. 13 (a) Relative change in MAPD as a function of angle of incidence for the nanostructured cell (a = 800nm, h = 1600nm) and a high-efficiency planar tandem cell. Data for both subcells of the tandem cell are shown. The lower of the two curves determines overall device performance. (b) Projected power conversion efficiencies for the nanostructured, single-junction planar and tandem planar cells as a function of angle of incidence, based on relative change in MAPD.

Download Full Size | PDF

Equations (2)

Equations on this page are rendered with MathJax. Learn more.

α i ( λ )= ∫ A i ω ε 0 ℑ( ε ) | E | 2 dxdy ∫ S ℜ{ E 0 × H 0 * } y ^  dx
J MAPD = ∫ 350nm 1000nm eλ hc I( λ ) α act ( λ )dλ
Select as filters
Select Topics Cancel
Top
       
© Copyright 2024 | Optica Publishing Group. All rights reserved, including rights for text and data mining and training of artificial technologies or similar technologies.
Privacy | Terms of Use