The stabilization of silicon(II) and germanium(II) dihydrides by an intramolecular Frustrated Lewis Pair (FLP) ligand, PB, i Pr­2P(C6H4)BCy2 (Cy = cyclohexyl) is reported. The resulting hydride complexes [PB{SiH2}] and [PB{GeH2}] are indefinitely stable at room temperature, yet can deposit films of silicon and germanium, respectively, upon mild thermolysis in solution. Hallmarks of this work include: (1) the ability to recycle the FLP phosphine‐borane ligand (PB) after element deposition, and (2) the single‐source precursor [PB{SiH2}] deposits Si films at a record low temperature from solution (110 °C). The dialkylsilicon(II) adduct [PB{SiMe2}] was also prepared, and shown to release poly(dimethylsilane) [SiMe2]n upon heating. Overall, this study introduces a “closed loop” deposition strategy for semiconductors that steers materials science away from the use of harsh reagents or high temperatures.