Method of producing a semiconducting material

A method of producing a semiconducting material having an optical band-gap E.sub.o of 0.1-4.0 eV, said method comprising:

• (a) reacting one or more halogenosilanes selected from the group consisting of halogenomonosilanes, halogenodisilanes, and halogenotrisilanes, with a co-reactant selected from the group consisting of alkali metals and alkaline earth metals, to produce a condensate;
• and
• (b) thermally decomposing said condensate;
• with the proviso that at least one of the one or more halogenosilanes used in step (a) and represented by the formulas (I)-(III) below has at least three substituents represented by X, wherein the halogenomonosilanes are represented by the formula (I) ##STR5## wherein X is selected from the group consisting of chlorine, bromine, and iodine;
• and R.sup.1 and R.sup.2 are independently selected from the group consisting of X, C.sub.3 -C.sub.12 secondary alkyls, C.sub.4 -C.sub.12 tertiary alkyls, C.sub.3 -C.sub.12 cycloalkyls, C.sub.8 -C.sub.12 primary aralkyls, C.sub.8 -C.sub.12 secondary aralkyls, C.sub.9 -C.sub.12 tertiary aralkyls, and silyl groups of the formula (I')
• R.sup.3 R.sup.4 R.sup.5 Si-- (I')
• wherein R.sup.3, R.sup.4 and R.sup.5 are independently selected from the group consisting of C.sub.1 -C.sub.8 alkyls and C.sub.6 -C.sub.10 aryls;
• and the halogenodisilanes are represented by the formula (II) ##STR6## wherein X is as defined above and R.sup.6 -R.sup.10 are independently selected from the group consisting of X, C.sub.3 -C.sub.12 secondary alkyls, C.sub.4 -C.sub.12 tertiary alkyls, C.sub.3 -C.sub.12 cycloalkyls, C.sub.8 -C.sub.12 primary aralkyls, C.sub.8 -C.sub.12 secondary aralkyls, C.sub.9 -C.sub.12 tertiary aralkyls and said silyl groups of the formula (I'), and at least one of R.sup.6 -R.sup.10 is X;
• and wherein the halogenotrisilanes are represented by the formula (III) ##STR7## wherein X is as defined above and R.sup.11 -R.sup.17 are independently selected from the group consisting of X, C.sub.3 -C.sub.12 secondary alkyls, C.sub.4 -C.sub.12 tertiary alkyls, C.sub.3 -C.sub.12 cycloalkyls, C.sub.8 -C.sub.12 primary aralkyls, C.sub.8 -C.sub.12 secondary aralkyls, C.sub.9 -C.sub.12 tertiary aralkyls, and said silyl groups of the formula (I'), and at least one of R.sup.11 -R.sup.17 is X.