The two approaches are addressed in the study for improving the efficiency of combustion-driven thermophotovoltaic(TPV) power system instead of material modification in photovoltaic cell and emitter. One is attempting to integrate visible wavelength from flames and near-infrared wavelength from the silicon carbide emitter for matching the quantum efficiency of nowadays PV cells. The other is coating metal-oxide-deposited layer on a quartz tube and acting as en emitter. Then, the metal-oxide-deposited emitter has advantages of high thermal diffusivity and easy-machining characteristics compare with the traditional emitter. Concept, design and demonstration on both tubular combustors are addressed and discussed in this paper. Results show that the two cost-effective strategies can significantly ameliorate the shortcomings of present PV cell and emitter, and apparently increase the radiation and quantum efficiency.