PRODUCTION METHOD OF COLLOIDAL LEAD SULFIDE PARTICLE, COLLOIDAL LEAD SULFIDE PARTICLE, AND SEMICONDUCTING FILM CONTAINING THE SAME

To provide a production method of a colloidal lead sulfide particle which has a peak value of an absorption spectrum of 1630 nm or more and 2100 nm or less and a narrow half-value width.SOLUTION: A production method of a colloidal lead sulfide particle comprises: a first step of preparing dispersed liquid of a colloidal lead sulfide particle A which has a peak value of an absorption spectrum of 900 nm or more and less than 1630 nm and a half-value width of the absorption spectrum of 120 nm or less; and a second step of adding a solution B with fatty acid lead dissolved therein and a solution C with a sulfur compound dissolved therein to the dispersed liquid of the colloidal lead sulfide particle A. A molar ratio between the fatty acid lead contained in the solution B and the sulfur compound contained in the solution C is 1.3:1.0 to 1.0:1.0. An absolute value of a difference in molar quantity between the fatty acid lead contained in the solution B and the sulfur compound contained in the solution C is 4.2×10-4 mol or less per 1 g of the colloidal lead sulfide particle A.SELECTED DRAWING: None 【課題】吸収スペクトルのピーク値が１６３０ｎｍ以上２１００ｎｍ以下で、かつ半値幅が狭いコロイド状硫化鉛粒子の製造方法を提供すること。【解決手段】吸収スペクトルのピーク値が９００ｎｍ以上１６３０ｎｍ未満であり、かつ吸収スペクトルの半値幅が１２０ｎｍ以下であるコロイド状硫化鉛粒子Ａの分散液を用意する第１の工程と、前記コロイド状硫化鉛粒子Ａの分散液に、脂肪酸鉛を溶解した溶液Ｂ、及び硫黄化合物を溶解した溶液Ｃを添加する第２の工程と、を有し、前記溶液Ｂに含まれる脂肪酸鉛と、前記溶液Ｃに含まれる硫黄化合物とのモル比は、１．３：１．０～１．０：１．０であり、前記溶液Ｂに含まれる脂肪酸鉛と、前記溶液Ｃに含まれる硫黄化合物とのモル量の差分の絶対値が、前記コロイド状硫化鉛粒子Ａの１ｇあたり４．２×１０－４モル以下である。【選択図】なし