23.2% laser processed back contact solar cell: fabrication, characterization and modeling

Abstract

We describe the manufacturing process for interdigitated back contact back junction silicon solar cells based on laser processes, and present detailed results and analysis to our best cell efficiency of 23.24%. The manufacturing process features two laser doping steps, one for the boron doped emitter and one for the phosphorus doped back surface field. The saturation current densities of thermal oxide passivated laser doped regions are on par with furnace diffused silicon for high efficiency solar cells. Laser ablation locally defines the contact areas through the rear dielectric layer stack, and structures the rear aluminum metallization. The precision of the laser systems in conjunction with the optical setup yields line shaped doping traces with a width of 150 µm and a pitch below 500 µm. The measured optical and electrical properties of our solar cell agree well with 3D simulation results. The measured reflection, transmission, quantum efficiency and current voltage curves in dark and illuminated condition simultaneously agree well with simulation, based on the same data set, giving confidence in the result of a detailed free energy loss analysis. The bulk resistive and recombination losses are identified as the main loss contributors. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Generation and Annealing of Crystalline Disorder in Laser Processing of Silicon

“…Laser processing has been widely studied for silicon device fabrication, including laser ablation, micro-texturing, doping, transfer of metal contacts, and annealing (Dahlinger et al 2017). The major challenge, however, is presented by laser-induced structural disorder and defects, which can dramatically degrade the electrical properties of laser-processed silicon and negatively affect the performance of laser-based photovoltaic (Hameiri et al 2010) and microelectronic (Arora and Dawar 1996) devices.…”

ZnO Kaplama Miktarının n-ZnO/p-Si Heteroeklem Güneş Hücresinin Verimliliğine Etkisi

“…Diğer taraftan, Tablo 1'de verilen güneş hücrelerinin verimlerinin, literatürdeki bir kısım güneş hücrelerinin verimlerine kıyasla, nispeten düşük olduğu görülmektedir [2][3][4][5][6][7][8]. Düşük verim, iki yarı iletken arasındaki tükenme bölgesindeki yüklerin yeniden birleşmesinden dolayı ya da gazların geçmesine izin verecek şekilde gözenekli bir yapıya sahip olan ZnO filminin yapısı nedeniyle olabilmektedir [26].…”

Fabrication of a 22.8% Efficient Back Contact Solar Cell With Localized Laser‐Doping

“…Dahlinger et al performed large‐area laser doping to minimize the required patterning steps and recently demonstrated a device efficiency of 23.2% with this process utilizing two‐different laser systems for four laser steps. Franklin et al demonstrated an all‐laser‐doped IBC cell concept using localized laser doping with a device efficiency of 19.1% while a cell with photolithographic patterning steps achieve 24.4% …”

“…However, we highlight, that these laboratory processes can be substituted with for instance laser‐patterning for contact separation (such as in Ref. ) or other low‐cost passivation techniques.…”