Silicon heterojunction rear emitter solar cells: Less restrictions on the optoelectrical properties of front side TCOs

Bivour, Martin; Schröer, Sebastian; Hermle, Martin; Glunz, Stefan W.

doi:10.1016/j.solmat.2013.11.029

Cited by 87 publications

(61 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similarly, the fill factor of the rear emitter hybrid(a-Si) cell is ∼0.15 % absolute higher than the rear emitter heterojunction cell. On a sidenote, the fill factor of the conventional front emitter heterojunction cell is ∼2 % absolute lower than the rear emitter heterojunction cell, due to additional lateral transport within the bulk of the c-Si wafer (see Figure 15), in accordance with the findings from Bivour et al 29 This also explains why the fill factor gain of rear emitter hybrid(a-Si) cells is much lower than for front emitter hybrid(a-Si) cells.…”

Section: Comparison Of Hybrid(a-si) Cells To Conventional Heterojusupporting

confidence: 89%

Three-dimensional numerical analysis of hybrid heterojunction silicon wafer solar cells with heterojunction rear point contacts

Ling

Duttagupta

et al. 2015

AIP Advances

View full text Add to dashboard Cite

This paper presents a three-dimensional numerical analysis of homojunction/heterojunction hybrid silicon wafer solar cells, featuring front-side full-area diffused homojunction contacts and rear-side heterojunction point contacts. Their device performance is compared with conventional full-area heterojunction solar cells as well as conventional diffused solar cells featuring locally diffused rear point contacts, for both front-emitter and rear-emitter configurations. A consistent set of simulation input parameters is obtained by calibrating the simulation program with intensity dependent lifetime measurements of the passivated regions and the contact regions of the various types of solar cells. We show that the best efficiency is obtained when a-Si:H is used for rear-side heterojunction point-contact formation. An optimization of the rear contact area fraction is required to balance between the gains in current and voltage and the loss in fill factor with shrinking rear contact area fraction. However, the corresponding optimal range for the rear-contact area fraction is found to be quite large (e.g. 20-60 % for hybrid front-emitter cells). Hybrid rear-emitter cells show a faster drop in the fill factor with decreasing rear contact area fraction compared to front-emitter cells, stemming from a higher series resistance contribution of the rear-side a-Si:H(p+) emitter compared to the rear-side a-Si:H(n+) back surface field layer. Overall, we show that hybrid silicon solar cells in a front-emitter configuration can outperform conventional heterojunction silicon solar cells as well as diffused solar cells with rear-side locally diffused point contacts.

show abstract

Section: Comparison Of Hybrid(a-si) Cells To Conventional Heterojusupporting

confidence: 89%

Three-dimensional numerical analysis of hybrid heterojunction silicon wafer solar cells with heterojunction rear point contacts

Ling

Duttagupta

et al. 2015

AIP Advances

View full text Add to dashboard Cite

show abstract

“…In addition, without any optical penalty, the back a-Si:H(p) layer could be thickened, thereby improving the screening of the c-Si wafer against the TCO. Notably, this architecture, exploiting better the substrate conductivity, relaxes the requirement for the front TCO lateral conductivity, and a highly conductive TCO is no longer required [44].…”

Section: Outlook On Transparent Electrodes For High-efficiency Simentioning

confidence: 99%

Transparent Electrodes in Silicon Heterojunction Solar Cells: Influence on Contact Passivation

Tomasi

Sahli

Seif

et al. 2016

IEEE J. Photovoltaics

View full text Add to dashboard Cite

Abstract-Charge carrier collection in silicon heterojunction solar cells occurs via intrinsic/doped hydrogenated amorphous silicon layer stacks deposited on the crystalline silicon wafer surfaces. Usually, both the electron and hole collecting stacks are externally capped by an n-type transparent conductive oxide, which is primarily needed for carrier extraction. Earlier, it has been demonstrated that the mere presence of such oxides can affect the carrier recombination in the crystalline silicon absorber. Here, we present a detailed investigation of the impact of this phenomenon on both the electron and hole collecting sides, including its consequences for the operating voltages of silicon heterojunction solar cells. Based on our findings, we define guiding principles for improved passivating contact design for high-efficiency silicon solar cells.

show abstract

“…This RE structure has several advantages to the front-emitter (FE) structure. 6,7 Since the emitter is located on the rear side, the emitter has less impact on the optical loss and it has more freedom for the design of structure, such as a surface morphology, a sheet resistance, and a grid pitch. In addition, the majority carrier transport (i.e., electron for n-type) is enhanced by the assistance of the Si substrate so that the grid pitch for the front side (n-doped side) can be wider without the significant increase in the series resistance.…”

Section: Introductionmentioning

confidence: 99%

Analysis of short circuit current loss in rear emitter crystalline Si solar cell

Watahiki

Kobayashi

Morioka

et al. 2016

Journal of Applied Physics

View full text Add to dashboard Cite

Short circuit current (Jsc) loss in rear emitter crystalline Si solar cell is analyzed in detail by a 2D device simulation and compared with the experimental results. There is a significant loss in Jsc for the rear emitter n-Si solar cell with an n-type doped front surface field (FSF) when the base substrate resistivity is low. It is due to an increase in recombination in the FSF region led by a less barrier height for minority carriers with a lower substrate resistivity. The barrier height less than 0.1 eV causes large loss in Jsc. To achieve higher Jsc for the cells with FSF, the control of the doping concentration in FSF, the substrate thickness, and the barrier height for the minority carriers are important. A rear emitter heterojunction Si solar cell with an amorphous Si passivation layer shows no substrate resistivity dependence on Jsc since an amorphous Si possess a higher barrier height and a long bulk lifetime of more than a few milliseconds.

show abstract

Silicon heterojunction rear emitter solar cells: Less restrictions on the optoelectrical properties of front side TCOs

Cited by 87 publications

References 46 publications

Three-dimensional numerical analysis of hybrid heterojunction silicon wafer solar cells with heterojunction rear point contacts

Three-dimensional numerical analysis of hybrid heterojunction silicon wafer solar cells with heterojunction rear point contacts

Transparent Electrodes in Silicon Heterojunction Solar Cells: Influence on Contact Passivation

Analysis of short circuit current loss in rear emitter crystalline Si solar cell

Contact Info

Product

Resources

About