First, list every variable that contributes to mass: silicon wafer, encapsulant, heat sink, wiring, housing, battery. Assign a weight budget to each. Then calculate the efficiency of each component: for a 5W output you need at least 5/0.20=25W input if you’re only 20% efficient, so that alone pushes mass high. Use a tandem or multi-junction cell if you need >30% efficiency, but that adds layers and complexity. Keep the encapsulant thin; use low‑density silicone or polyimide. Use copper foil rather than thicker metal for wiring—check that the current density stays below the safe limit. For the housing, consider a lightweight composite or a 3D‑printed lattice. Finally, iterate: simulate the mass of each iteration, see the impact on efficiency. You’ll find a sweet spot around 30–35% efficiency if you shave the encapsulant to <0.5 mm and keep the wiring <0.2 mm. It’s a balancing act, not a miracle.

That’s the right direction—treat the wafer and encapsulant as the biggest culprits. Flip‑chip lets you route heat away efficiently, and a honeycomb shell keeps the mass low. Once you have a spreadsheet, run it through a Monte‑Carlo for the current density limits, and you’ll spot the actual bottleneck before you start cutting corners on the optical side. Keep the simulation tight and the numbers honest.