No abstract

In good silicon solar cells, the separation of the quasi-Fermi energies Δη in the bulk is equivalent to the cell voltage. Photoluminescence is used to measure Δη in both bifacial solar cells and partly processed solar cells. The bifacial cells are used to demonstrate that simultaneous measurement of the photoluminescence signal and of the variable incident light intensity yields pseudo current-voltage characteristics, equivalent to Suns-open circuit voltage (VOC) measurements, but in contactless mode. The applicability of this method to unfinished solar cells, without the need for a solar cell structure, is demonstrated on silicon wafers after various processing steps.

A process using laser‐ablated pits to texture the front surface of monocrystalline and multicrystalline silicon solar cells is described. Optical and electrical characterization demonstrates that the technique performs as well as upright random pyramid texturing and causes no laser‐induced defects or laser shunting. Double‐sided buried contact solar cells fabricated with laser texture performed as well as those fabricated with upright random pyramid textures on 1 Ω cm, p type float‐zoned wafers. Copyright © 2006 John Wiley & Sons, Ltd.

In this letter, we demonstrate good surface passivation of lightly diffused n-type solar cell emitters using titanium dioxide (TiO2) thin films treated with a furnace oxidation process. Transient-photoconductance decay, x-ray photoelectron spectroscopy, and scanning electron microscopy measurements indicate that the silicon dioxide layer formed at the TiO2:Si interface provides excellent surface passivation. Emitter dark saturation current densities of 4.7×10−14 A/cm2 are achieved by this method, demonstrating that TiO2 films are compatible with high-efficiency solar cell structures.