Investigation of electrical shading loss of bifacial interdigitated-back-contact (IBC) crystalline silicon solar cells with screen-printed electrode

Abstract

N-type bifacial interdigitated-back-contact (IBC) crystalline silicon solar cells were processed with screen-printed electrodes. The bifacial IBC cells resulted in a drastic decrease of the electrical shading loss at the finger region with decreasing pitch on the rear side. This loss was dominated by the width of the base region. In addition, passivation properties also affected carrier recombination in the base region. A narrower base region and smaller pitch led to higher internal quantum efficiency and low series resistance. Cell efficiency of over 22% was obtained for the bifacial IBC crystalline silicon solar cells with a base region width of 250 μm and pitch of 1250 μm. The IQE values above the emitter and base region at medium wavelengths were over 95% and 90%, respectively. Using these cells, a mini-module showing 19.4% module efficiency with 78.1% FF was created.

Trap-Assisted Dopant Compensation Prevents Shunting in Poly-Si Passivating Interdigitated Back Contact Silicon Solar Cells

“…Using this simulation methodology, we calculated a shunt resistance of ∼10 9 Ω·cm 2 for our experimentally measured dopant profiles. For the dopant tails reported in ref , we calculate R shunt ≈ 8 MΩ·cm 2 across a 30 μm wide isolation region, which is on the same order of magnitude as reported by these authors in ref . While the resistor model is clearly an imperfect approximation, it appears to be suitable to estimate the location, width, and approximate R shunt of the compensated region.…”

“…IBC solar cells are a very promising architecture for Si PV due to their high short-circuit current density, J sc , which is due to the lack of front shading loss and no parasitic absorption from a-Si:H or poly-Si at the front of the device. IBC cells can also be made bifacial, − and thus have great potential to enter the mainstream Si PV market. However, more cost-effective, simpler processing techniques are needed, especially for forming highly passivated IBC finger structures at the back of the cell with no shunting.…”

Evaluating the Practical Efficiency Limit of Silicon Heterojunction–Interdigitated Back Contact Solar Cells by Creating Digital Twins of Silicon Heterojunction Solar Cells with Amorphous Silicon and Nanocrystalline Silicon Hole Contact Layers

“…The gap isolating the HSC and the ESC causes efficiency losses due to the electrical shading effect. [ 34 ] This is because increased recombination in this region reduces the probability of carrier collection. SHJ–IBC cells featuring p‐nc‐Si:H HSCs can achieve a boosted maximum efficiency of 27.51% by reducing the gap width from 80 to 20 μm.…”