Wavelength converters (103) with improved thermal conductivity are described. In some embodiments the wavelength converters include a thermally conductive component (204, 206) and a wavelength conversion material (205) mixed with or dispersed in the thermally conductive component. The wavelength conversion material (205) includes non-agglomerated quantum dots. The presence of the thermally conductive component may facilitate removal of heat from the wavelength converter, potentially reducing the impact of elevated temperature on the performance of the wavelength conversion material therein. Methods of making such wavelength converters and lighting devices including such wavelength converters are also described.