Perovskite/silicon tandem solar cells promise power conversion efficiencies beyond the Shockley–Queisser limit of single-junction devices; however, their actual outdoor performance is yet to be investigated. Here we fabricate 25% efficient two-terminal monolithic perovskite/silicon tandem solar cells and test them outdoors in a hot and sunny climate. We find that the temperature dependence of both the silicon and perovskite bandgaps—which follow opposing trends—shifts the devices away from current matching for two-terminal tandems that are optimized at standard test conditions. Consequently, we argue that the optimal perovskite bandgap energy at standard test conditions is <1.68 eV for field performance at operational temperatures greater than 55 °C, which is lower compared with earlier findings. This implies that bromide-lean perovskites with narrower bandgaps at standard test conditions—and therefore better phase stability—hold great promise for the commercialization of perovskite/silicon tandem solar cells.

钙钛矿/硅串联太阳能电池的功率转换效率有望超过单结器件的Shockley-Queisser限制。但是，它们的实际户外性能还有待研究。在这里，我们制造了效率为25％的两端整体式钙钛矿/硅串联太阳能电池，并在炎热和阳光充足的室外进行了测试。我们发现，硅和钙钛矿带隙的温度依赖性（遵循相反的趋势）使器件远离电流匹配，而电流匹配是针对在标准测试条件下进行了优化的两端tandem进行的。因此，我们认为，在高于55°C的工作温度下，对于现场性能而言，在标准测试条件下的最佳钙钛矿带隙能<1.68 eV，与早期的发现相比更低。