Triphenylgermylsilane (Ph3Ge—SiH3) is useful for the production of germanium-silicon layers (Ge—Si) or as transfer agent of silane groups (SiH3). Further, a method describes the production of triphenylgermylsilane (Ph3Ge—SiH3) by reducing trichlorosilyl-triphenylgermane (Ph3Ge—SiCl3) with a hydride in solution, and another method describes the production of trichlorosilytrichlorogermane (Cl3Ge—SiCl3) by reacting trichlorosilyltriphenyigermane (Ph3Ge—SiCl3) with hydrogen chloride (HCl) in the presence of AlCl3 in solution. In addition, trichlorosilyltrichlorogermane is also used for the production of germanium-silicon layers (Ge—Si).