The design and numerical analysis of tandem thermophotovoltaic cells

In this paper, numerical analysis of GaSb (E_g=0.72 eV)/Ga_0.84In_0.16As_0.14Sb_0.86 (E_g=0.53 eV) tandem thermophotovoltaic (TPV) cells is carried out by using Silvaco/Atlas software. In the tandem cells, a GaSb p–n homojunction is used for the top cell and a GaInAsSb p–n homojunction for the bottom cell. A heavily doped GaSb tunnel junction connects the two sub-cells together. The simulations are carried out at a radiator temperature of 2000 K and a cell temperature of 300 K. The radiation photons are injected from the top of the tandem cells. Key properties of the single-and dual-junction TPV cells, including I–V characteristic, maximum output power (P_max), open-circuit voltage (V_oc), short-circuit current (I_sc), etc. are presented. The effects of the sub-cell thickness and carrier concentration on the key properties of tandem cells are investigated. A comparison of the dual-TPV cells with GaSb and GaInAsSb single junction cells shows that the P_max of tandem cells is almost twice as great as that of the single-junction cells.