Gasfassyntes

Gasfassyntes, also called gas-phase synthesis, refers to chemical synthesis conducted primarily in the vapor phase, with little to no use of liquid solvents. In this approach reactants are introduced as gases or vapors and react to form products either in the gas phase or on solid substrates. The method encompasses a range of processes designed to deposit, grow, or assemble materials from gaseous precursors.

Key methods include chemical vapor deposition (CVD), where volatile precursors react or decompose on a substrate to form a thin film; plasma-enhanced CVD (PECVD), which uses plasma to promote reactions at lower temperatures; and atomic layer deposition (ALD), a sequential gas-phase process that builds films one monolayer at a time. Gas-phase synthesis also covers homogeneous gas-phase reactions that yield nanoparticles or volatile intermediates, as well as gas-phase pyrolysis and condensation.

Applications span electronics and photonics, where CVD and ALD are used to create semiconductor films and coatings; energy technologies such as photovoltaic and battery materials; catalysis, where metal or oxide nanoparticles are generated in the vapor and deposited; and protective coatings for corrosion and wear resistance.

Advantages include high purity and conformal film deposition, solvent-free processing, and good scalability for large-area coatings. Challenges include controlling composition, stoichiometry, morphology, and thickness at the nanoscale, requiring precise precursors and process conditions; high-temperature operation and safety concerns related to toxic or reactive gases; and equipment costs. Related concepts include chemical vapor deposition and atomic layer deposition, which are common techniques within gas-phase synthesis.