Some embodiments include an integrated assembly having a first semiconductor material between two regions of a second semiconductor material. The second semiconductor material is a different composition than the first semiconductor material. Hydrogen is diffused within the first and second semiconductor materials. The conductivity of the second semiconductor material increases in response to the hydrogen diffused therein to thereby create a structure having the second semiconductor material as source/drain regions, and having the first semiconductor material as a channel region between the source/drain regions. A transistor gate is adjacent the channel region and is configured to induce an electric field within the channel region. Some embodiments include methods of forming integrated assemblies.