Bifacial, large-area silicon sensors for radiative energy signals

Abstract

A comprehensive design/technological study was conducted with the aim of obtaining high-quality, bifacial optical sensors with reproducible parameters on large-area n- and p- silicon wafers. Practical ways of attenuating the severe limitations imposed by different kinds of material (areal) inhomogeneities on the electro-optical performance of large-area singlecrystal silicon sensors for radiative energy signals are described theoretically and tested experimentally. Various procedures leading to a substantial increase of both the emitter and the base contributions to the generated photocurrent are implemented and discussed in detail. The test devices were processed on 2 and 3 inch commercially-available silicon and it was sought to minimize the cost of the cells. The combination of simple design/technological approaches described in this work has ultimately led to the development of low-cost, high-quality large-area silicon sensors with good overall electro-optical performance as bifacial devices. The results of this work show clearly that simple, but adequately designed and processed devices fabricated on an industrial scale on large-area silicon wafers could possess parameters similar to those of sophisticated laboratory samples elaborated on small-area silicon chips. With the outlined design/technological approaches, the use of even cheaper, i.e., lower-grade, single-crystal, silicon could still yield large-area sensors for radiative energy signals with fairly acceptable electro-optical performance.