以天然黄铁矿为样本,用Cary500型紫外可见近红外分光光度计在200~2000nm范围内测出了样品的吸收谱和反射谱,计算出了吸收系数,并根据Tauc规则算出了样品的禁带宽度。结果表明:所测天然黄铁矿光吸收系数在10^5数量级;在吸收图谱中出现了明显的肩行结构,可以判断样品属于间接禁带半导体,其禁带宽度为0.64eV,对应的“极限转换效率”可达到14%左右;将结果与现在常用的太阳能电池材料进行比较,分析讨论了光吸收系数和禁带宽度对黄铁矿光电转换效率的影响。认为:天然黄铁矿高的吸收系数为黄铁矿以薄膜的形式用作太阳能电池提供了可能,但是其禁带宽度与理论计算值相比偏小,可考虑展宽其禁带宽度或制成复合薄膜使用。
In the present paper, the natural pyrite was the sample. With the UV-visible near-infrared spectrophotometer Cary 500, we measured the absorption and reflection spectra of the sample within 200~2 000 nm range, calculated the absorption co- efficient and figured out the forbidden band of the sample according to the Taue regulation. The authors discovered that the light absorption coefficient of natural pyrite measured is 105 order of magnitude; in the absorption pattern we found obvious shoulder line structure and we can judge that the sample belongs to indirect forbidden band semiconductor, its forbidden band was 0. 64 eV in width and the "limit conversion efficiency" corresponding to 0. 64 eV could reach 14% or so. With the comparison of the results of this paper and the forbidden band of the solar battery materials at present in common, this paper mainly analyzed the effect of the light absorption coefficient and forbidden band on the photoelectric conversion efficiency of pyrite. The authors found that its high absorption coefficient provided the possibility that pyrite will be used as solar battery with the film form, but its forbidden band was narrower than the theoretical number. The authors could broaden its forbidden band or make composite films to use.