Optical Design of Inverted Pyramid Textured PERC Solar Cells

Abstract

Single side optical design of solar cells has limitations. In this paper, we studied the optical properties of inverted pyramid textured passivated emitter and rear cell (PERC) solar cells, considering different combinations of front and rear inverted pyramid angles. Ray tracing simulations were conducted to obtain a macro insight, and then experiments were performed under the conditions of practical applications. According to an analysis of the results, the overall optical properties are shown to be positively correlated to the front side inverted pyramid angle, and the influence of the rear side inverted pyramid angle strongly depends on the front side inverted pyramid angle. In practical applications, double-sided inverted pyramids with an angle of 54.74° can be efficiently fabricated on silicon wafers etched by the metal catalysis chemical etching (MCCE) method. Maintaining the front surface morphology as etched, wafers with small-angle (10°–20°) inverted pyramids at the rear side has an ∼1.66% improvement in optical gain compared with totally planarized rear side wafers; meanwhile, the rear side passivation effect does not change much. Thus, it is a better choice to have small-angle structures on the rear side. Our results could serve as a guide for the texturization and rear side polishing of inverted pyramid textured PERC solar cells.

Improvement of Light Trapping in Bifacial PERC Silicon Solar Cells by Optimizing the Rear Surface Morphology

“…In addition, it is well known that the rear morphology also has a significant effect on rear surface passivation. Thus, for bi-PERC solar cells, the polishing degree of the rear pyramids is required to achieve a trade-off between front-side light trapping, rear-side light trapping, and rear surface passivation . Next, we focus on the further experimental study and analysis of the impact of various rear morphologies on the electrical performance of bi-PERC solar cells.…”

Electroluminescence as a Tool to Study the Polarization Characteristics and Generation Mechanism in Silicon PV Panels

“…When the photovoltaic cell is connected to the forward bias voltage, the carrier balance is broken, so that the electrons and holes can pass through the PN junction and become unbalanced carriers. The unbalanced carriers compound with majority carriers and radiate outward; this is called electroluminescence [14], and is shown in Figure 1.…”

Optical simulation of CsPbI3/TOPCon tandem solar cells with advanced light management

“…Our previous work indicated that the b-IP texture with a small θ in a range of 10.0 • -20.0 • can improve the optical gain of PERC compared with the quintessential 54.7 • . [39] The mass producible inverted pyramid structure fabricated by Cu-assisted chemical etching is usually bifacial texture. [40] On the other hand, θ can be gradually reduced by controllable single-side etching in HF/HNO 3 /H 2 O mixture, [39] which guarantees that the following simulation of the inverted pyramid textured TSCs with θ varying from 0.0 • to 54.7 • is instructive and practicable.…”

“…Our previous work have illustrated that when θ > 4 • , the reflection in the front interface of TSCs will generally decrease with the increase of θ because of the enhanced probability of total internal reflection; when θ < 24 • , the transmission in the rear interface of TSC will be suppressed for the same reason. [39] Therefore, a small θ can make a trade-off between reflection and transmission, contributing to a higher J G Si . Thus, in order to maximize the optical harvest in PVK/Si TSCs, the rear side texture should become smoother, which will be simultaneously beneficial to the passivation of the rearside surface of Si subcell.…”