Molecule-based selective contacts have become a crucial component to ensure high-efficiency inverted perovskite solar cells^1,2,3,4,5. These molecules always consist of a conjugated core with heteroatom substitution to render the desirable carrier-transport capability^6,7,8,9. So far, the design of successful conjugation cores has been limited to two N-substituted π-conjugated structures, carbazole and triphenylamine, with molecular optimization evolving around their derivatives^2,5,10,11,12. However, further improvement of the device longevity has been hampered by the concomitant limitations of the molecular stability induced by such heteroatom-substituted structures^13,14. A more robust molecular contact without sacrificing the electronic properties is in urgent demand, but remains a challenge. Here we report a peri-fused polyaromatic core structure without heteroatom substitution that yields superior carrier transport and selectivity over conventional heteroatom-substituted core structures. This core structure produced a relatively chemically inert and structurally rigid molecular contact, which considerably improved the performance of perovskite solar cells in terms of both efficiency and durability. The champion device showed an efficiency up to 26.1% with greatly improved longevity under different accelerated-ageing tests.

基于分子的选择性接触已成为确保高效倒置钙钛矿太阳能电池的关键组成部分 ^1,2,3,4,5 。这些分子始终由具有杂原子取代的共轭核心组成，以提供所需的载流子传输能力 ^6,7,8,9 。到目前为止，成功的共轭核的设计仅限于两种N-取代的π-共轭结构，咔唑和三苯胺，分子优化围绕它们的衍生物 ^2,5,10,11,12 不断发展。然而，这种杂原子取代结构 ^13,14 导致的分子稳定性的限制阻碍了器件寿命的进一步提高。迫切需要在不牺牲电子性能的情况下实现更稳健的分子接触，但这仍然是一个挑战。在这里，我们报道了一种没有杂原子取代的全稠合聚芳族核心结构，与传统的杂原子取代的核心结构相比，它具有优异的载流子传输和选择性。这种核心结构产生了相对化学惰性和结构刚性的分子接触，这大大提高了钙钛矿太阳能电池的效率和耐用性。在不同的加速老化测试中，冠军器件的效率高达 26.1%，并且寿命大大提高。