Phosphorus emitter engineering by plasma-immersion ion implantation for c-Si solar cells

Abstract

Ion Beam Services (IBS) has developed processes dedicated to silicon-based solar cell manufacturing using a plasma-immersion ion implantation equipment. It enables the realization of various doping profiles for phosphorus-doped emitters which fit the requirements of high-efficiency solar cells. PH 3 plasma-implanted emitters are chemically, physically and electrically characterized to demonstrate their excellent quality. Those emitters are then integrated into a low cost p-type monocrystalline silicon solar cell manufacturing line from the National Solar Energy Institute (INES) in order to be compared with usual POCl 3 diffusion. Starting from a basic process flow with blanket emitter and conventional full-area aluminum back-surface field, plasma-immersion implanted emitters enable to raise conversion efficiencies above 19.1%. Thanks to an optimized double layer anti-reflective coating, a 19.4% champion cell has been achieved. Depending on different plasma process parameters, lightly doped emitters are then engineered aiming to study doping modulation using a dedicated laser.

Nitrogen Ion Beam‐Mediated Dry Patterning of Conjugated Polymer Films for Organic Field‐Effect Transistors

“…[11,12] Ion beams, which are composed of ionized atoms or molecules, have been widely used for ion implantation (doping) processes in semiconductor industries in order to modify the nature of inorganic semiconducting materials (e.g., boron or phosphorous doping for Si wafers). [13,14] In addition, the ion beams with a high kinetic energy have been introduced to enhance the mechanical strength of inorganic and/or metallic components such as titanium and nickel. [15,16] In particular, it has been reported that the irradiation of ion beams can alter the chemical structure of polymers.…”

Plasma‐immersion ion implantation: A path to lower the annealing temperature of implanted boron emitters and simplify PERT solar cell processing

“…As‐implanted boron and phosphorus concentration profiles measured by secondary‐ion mass spectroscopy (SIMS). Gaussian profile of beamline ion implantation (BLII) implant of B + ions at 10 keV and 1.2 × 10 15 at/cm 2 (BLII_asImp) compared with plasma‐immersion ion implantation (PIII) implants from B 2 H 6 and PH 3 gas precursors with two different implantation energies in the PH 3 case, 4 and 8 kV (SIMS from Michel et al) [Colour figure can be viewed at wileyonlinelibrary.com]…”

Solar‐grade boron emitters by BF3 plasma doping and role of the co‐implanted fluorine

“…The latter tool is potentially the cheapest one (taking into account running costs) as it is a non mass‐selective, surface‐independent, low gas consuming implantation equipment. High‐quality phosphorous PIII emitters have been largely validated these last years, leading to conversion efficiencies quite above 19% on p‐type industrial size silicon cells with aluminum back surface field . Besides, plasma immersion could also serve as a texturization method (black silicon) compatible with the conformal doping of surfaces showing high aspect ratios .…”