A　new　class　of　white　luminescent　materials,　white-light-emitting　graphene　quantum　dots　(WGQDs),　have　attracted　increasing　attention　because　of　their　unique　features　and　potential　applications.　Herein,　we　designed　and　synthesized　a　novel　WGQDs　VIA　a　solvothermal　molecular　fusion　strategy.　The　modulation　of　chlorine　doping　amount　and　reaction　temperature　gives　the　WGQDs　a　single-crystalline　structure　and　bright　white　fluorescence　properties.　In　particular,　the　WGQDs　also　exhibit　novel　and　robust　white　phosphorescence　performance　for　the　first　time.　An　optimum　fluorescence　quantum　yield　of　WGQDs　is　34%,　which　exceeds　the　majority　of　reported　WGQDs　and　other　white　luminescent　materials.　The　WGQDs　display　broad-spectrum　absorption　within　almost　the　entire　visible　light　region,　broad　full　width　at　half　maximum　and　extend　their　phosphorescence　emission　to　the　entire　white　long-wavelength　region.　This　unique　dual-mode　optical　characteristic　of　the　WGQDs　originates　from　the　synergistic　effect　of　low-defect　and　high　chlorine-doping　in　WGQDs　and　enlarges　their　applications　in　white　light　emission　devices,　cell　nuclei　imaging,　and　information　encryption.　Our　finding　provides　us　an　opportunity　to　design　and　construct　more　advanced　multifunctional　white　luminescent　materials　based　on　metal-free　carbon　nanomaterials.