TY - JOUR

T1 - Inductively coupled plasma chemical vapour deposited AlO x/SiNy layer stacks for applications in high-efficiency industrial-type silicon solar cells

AU - Dullweber, T.

AU - Kranz, C.

AU - Beier, B.

AU - Veith, B.

AU - Schmidt, J.

AU - Roos, B. F.P.

AU - Hohn, O.

AU - Dippell, T.

AU - Brendel, R.

N1 - Funding Information: We thank our colleagues at ISFH for support in solar cell processing as well as Heraeus and Ferro for the screen printing pastes. We thank Tom Falcon from DEK for the fruitful collaboration on improving the front side screen printing process. This work was funded by the German Federal Ministry for the Environment , Nature Conservation and Nuclear Safety within the R&D projects HighScreen and ALBA II and by our industry partners Singulus Technologies, Rena, Schott Solar, Solar World, and Q-Cells.

PY - 2013

Y1 - 2013

N2 - Passivated emitter and rear cells (PERC) are considered to be the next generation of industrial-type screen-printed silicon solar cells. Deposition methods for rear passivation layers have to meet both the high-throughput and low-cost requirements of the PV industry in combination with high-quality surface passivation properties. In this paper, we evaluate and optimise a novel deposition technique for AlOx passivation layers by applying an inductively coupled plasma (ICP) plasma-enhanced chemical vapour deposition (PECVD) process. The ICP AlOx deposition process enables high deposition rates up to 5 nm/s as well as excellent surface recombination velocities below 10 cm/s after firing. A fixed negative charge of -4×1012 cm-2 is measured for ICP AlOx single layers with an interface state density of 11.0×1011 eV-1 cm-2 at midgap position. When applied to PERC solar cells the ICP AlOx layer is capped with a PECVD SiNy layer. We achieve independently confirmed conversion efficiencies of up to 20.1% for large-area (15.6×15.6 cm2) PERC solar cells with screen-printed metal contacts and ICP AlOx/SiNy rear side passivation on standard boron-doped Czochralski-grown silicon wafers. The internal quantum efficiency reveals an effective rear surface recombination velocity Srear of (90±30) cm/s and an internal rear reflectance Rb of (91±1)% which demonstrates the excellent rear surface passivation of the ICP AlOx/SiNy layer stack.

AB - Passivated emitter and rear cells (PERC) are considered to be the next generation of industrial-type screen-printed silicon solar cells. Deposition methods for rear passivation layers have to meet both the high-throughput and low-cost requirements of the PV industry in combination with high-quality surface passivation properties. In this paper, we evaluate and optimise a novel deposition technique for AlOx passivation layers by applying an inductively coupled plasma (ICP) plasma-enhanced chemical vapour deposition (PECVD) process. The ICP AlOx deposition process enables high deposition rates up to 5 nm/s as well as excellent surface recombination velocities below 10 cm/s after firing. A fixed negative charge of -4×1012 cm-2 is measured for ICP AlOx single layers with an interface state density of 11.0×1011 eV-1 cm-2 at midgap position. When applied to PERC solar cells the ICP AlOx layer is capped with a PECVD SiNy layer. We achieve independently confirmed conversion efficiencies of up to 20.1% for large-area (15.6×15.6 cm2) PERC solar cells with screen-printed metal contacts and ICP AlOx/SiNy rear side passivation on standard boron-doped Czochralski-grown silicon wafers. The internal quantum efficiency reveals an effective rear surface recombination velocity Srear of (90±30) cm/s and an internal rear reflectance Rb of (91±1)% which demonstrates the excellent rear surface passivation of the ICP AlOx/SiNy layer stack.

KW - AlO

KW - Aluminium oxide

KW - Inductively coupled plasma

KW - Rear passivation

KW - Screen printing

KW - Silicon solar cells

UR - http://www.scopus.com/inward/record.url?scp=84874612608&partnerID=8YFLogxK

U2 - 10.1016/j.solmat.2013.01.036

DO - 10.1016/j.solmat.2013.01.036

M3 - Article

AN - SCOPUS:84874612608

VL - 112

SP - 196

EP - 201

JO - Solar Energy Materials and Solar Cells

JF - Solar Energy Materials and Solar Cells

SN - 0927-0248

ER -