El. Jackson et Am. Barnett, MINORITY-CARRIER COLLECTION ENHANCEMENT MODEL FOR THE DEEPLY GROOVED SOLAR-CELL, Progress in photovoltaics, 3(6), 1995, pp. 403-412
Although many, solar cell designs for low-concentration linear focus a
pplications have utilized the 'prismatic cover' for reducing gridline
shading, the deeply grooved solar cell represents an effort to integra
te the prismatic cover into the basic device design for performance en
hancement. The design is based on deep (140-mu m) grooves in [100] ori
entation silicon, with an active-area silicon 'ridge' between gridline
s. The silicon ridge should improve minority carrier collection effici
ency, as compared to planar designs, due to the two-dimensional nature
of current collection, and the placement of light on the ridge by the
focus of the prismatic cover. This article describes the enhancement
mechanism by using a model based on the superposition of two specific
solutions of the transport equation. The enhancement model is in suppo
rt of the approximation that for one-dimensional numerical modeling, t
he 'effective' diffusion length is the sum of the bulk silicon diffusi
on length and the height of the ridge. Data collected from prototype s
olar cells provide some experimental support for the model, but diffic
ulty in fabrication using typical semiconductor processing has limited
full realization of the structure.