Series resistance characterization of industrial silicon solar cells with screen‐printed contacts using hotmelt paste

Abstract

This work presents the results of a detailed series resistance characterization of silicon solar cells with screen-printed front contacts using hotmelt silver paste. Applying the hotmelt technology energy conversion efficiencies up to 18.0% on monocrystalline wafers with a size of 12.5 cut X 12.5 cut have been achieved, an increase of 0.3% absolute compared to cells with conventional screen-printed contacts. This is mainly due to the reduction in the finger resistance to values as low as 14 Omega/m, which reduces the series resistance of the solar cell significantly. To retrieve the lumped series resistance as accurately as possible under the operating condition, different determination methods have been analyzed. Methods under consideration were fitting of the two-diode equation function to a dark IV-curve, integration of the area A under an IV-curve, comparison of a j(sc)-V-oc with a one-sun IV-curve, comparison of the jsc and V-oc points of a shaded curve with the one-sun IV-curve as well as comparison of a dark IV-curve with a one-sun IV-curve, and comparison of IV-curves measured at different light intensities. The performed investigations have shown that the latter four methods all resulted in reliable series resistance values

Origin of Radiation‐Induced Degradation in Polymer Solar Cells

“…The analysis of dark I-V curves was based on a commonly accepted one-diode circuit model. [ 15 ] While the conventional methods normally fi ts the dark I-V curves and get the parameters of the p-n junction and series ( R s )/shunt ( R sh ) resistance directly, we fi rst calculate the R s based on the comparison between dark and light I-V curves. [ 16 , 17 ] According to theoretical as well as experimental studies, [ 18 ] the R s extracted this way is more accurate compared to the one obtained by fi tting the slope at the high voltage end, since it considers the different current fl ow patterns under dark and under illumination, and the multi-dimensional effect of the R s .…”

Front-side metal electrode optimization using fine line double screen printing and nickel plating for large area crystalline silicon solar cells

“…As the finger spacing increased from 1.8 mm to 2.6 mm, the shadowing losses linearly decreased and the J SC increased. Although the decrease of shadowing loss was caused by the broadening of the finger spacing, the FF and the conversion efficiency decreased due to the increase of the series resistance [13,14].…”

“…contact and series resistance of the front finger increased due to the decrease of the grid area [13,14]. The FE-SEM (Field Emission-Scanning Electron Microscope) images of the material content without and with nickel plating front electrode was shown in Fig.…”

Insights into metastability of photovoltaic materials at the mesoscale through massiveI–Vanalytics

“…[31][32][33] Research on the conductive lines has typically focused on the conductor line microstructure throughout the firing process 34 and the interface between the screen-printed conductive lines and the emitter as a function of precursor constituents to optimize the initial electrical performance. 30,[34][35][36][37][38] The microscopic mechanisms that result in the formation of the low resistance contact between the silver conductive lines and the solar cell are still being uncovered, 28 but two prevailing models are generally accepted. One hypothesis suggests that the Ag becomes dissolved within the molten glass frit, and upon cooling down, the supersaturated solution allows large grain growth at the Si interface causing a Schottky-barrierlike boundary that acts more Ohmic as the emitter doping concentration is increased to n þþ levels.…”