Crystalline Silicon Solar Cells With Coannealed Electron- and Hole-Selective SiC _x Passivating Contacts

Highly passivating and blister-free hole selective poly-silicon based contact for large area crystalline silicon solar cells

“…By fabricating similar samples using better quality KOH-polished 156psq n-type Cz c-Si wafers, an average iVoc of 731 mV was obtained after annealing at Ta = 700°C with a best value of 734 mV (corresponding to a J0 of 7 fA•cm -2 ). This is among the best values obtained so far with p + -poly-Si symmetrical samples on planar surface (in the range 732-735 mV for iVoc and 1-10 fA•cm -2 for J0) [14,20,21,23]. Values of 720 mV and 10 fA•cm -2 were also demonstrated on textured surface [22].…”

“…So far, hole-selective poly-Si/SiOx structures have been mainly formed with boron-doped poly-Si layer (poly-Si(B)) and have historically demonstrated lower passivation performances compared to their phosphorus counterparts [17]. Despite recent progress achieved with poly-Si(B)/SiOx passivating structures on both planar and textured surfaces [20][21][22], boron (B) is suspected to cause more defects in the structure, especially at the interface with the SiOx layer [23], due to low B diffusivity in SiOx leading to B atoms piling-up at the SiOx layer [24,25].…”

Role of silicon surface, polished 〈100〉 and 〈111〉 or textured, on the efficiency of double‐sided TOPCon solar cells

“…15,19,20 PCE about 19.6% is reported using TCO-free device with T-seeded Cu-plated front contact, 20 and the best PCE about 22.6% used doped silicon carbide on front-side textured and backside polished. 21 To further enhance the PCE, it is necessary to study the role of the surface orientation h100i or h111i and the effect of polished or textured surfaces as a function of the ultrathin SiO x thickness.…”

SiOxNy:B layers for ex-situ doping of hole-selective poly silicon contacts: A passivation study

“…First, a thin SiO x layer (~1. 3 in-situ doped poly-Si(B) layers were prepared by PECVD of 25 nm-thick B-doped a-Si:H layers on both sides of the wafer using H 2 -diluted diborane (B 2 H 6 ) as doping precursor gas and followed by an annealing step under argon (T a = 700-900°C) to crystallize the layer and activate dopants. Ex-situ doped poly-Si(B) layers were prepared by PECVD of a SiO x N y :B layer on top of a 25 nm-thick intrinsic Si layer deposited by PECVD, followed by the same annealing step to ensure dopant diffusion and activation.…”

“…Passivating the contacts of c-Si solar cells with a polycrystalline silicon (poly-Si) layer on top of a thin silicon oxide (SiO x ) is known to reduce carrier recombination at the interface between the metal electrodes and the c-Si substrate [1][2][3] . In this study we focused on boron-doped poly-Si (poly-Si(B)) structures which are of prime interest to passivate the rear side of next-generation PERC solar cells.…”