Effect of Sub-Grains and Crystal Defects on Monolike Si Solar Cell Performance

Abstract

<p class="MsoNormal" style="text-align:justify;"> <span lang="EN-US">This paper investigates crystalline orientation in monolike silicon wafers and its effect on solar cell performance. Monolike silicon wafers from two different bricks cut from interior and corner region of an ingot were compared. The mono grain in the interior brick is nearly perfect, but there are some large oblong shaped sub-grains in the corner brick. The large sub-grains at corner brick wafers are oriented at (311), instead of (100) orientation. The (311) grains contain high density of dislocation and cannot be effectively textured by alkaline solution, therefore lowering the cell efficiency significantly. There is about 0.86% (abs) cell efficiency reduction on the monolike cells that contain large sub-grains.</span> </p

Polarized light emission from grain boundaries in photovoltaic silicon

“…Wafers typically only contain single grains through their thickness. Grain size is regarded as an important factor, since smaller grain size introduces more grain boundaries, which are potentially deleterious features [4,5]. However, the presence of defect structures or grain boundaries alone does not directly correlate to reduced solar cell performance.…”

Recombination activity of sub-grain boundaries and dislocation arrays in quasi-single crystalline silicon

“…9) It has been reported that sub-GBs in QSC silicon, originating from lattice mismatch between adjacent seeds, can severely degrade the solar cell performances. [10][11][12][13][14][15][16][17] It was found that the misorientation of such sub-GBs in QSC silicon is usually smaller than 3°, 10) which belong to small-angle (SA) GBs. Up to now, substantial research efforts have been devoted to the investigation on the recombination activity of SA GBs.…”