Perovskite solar cells are cheap, printable and nearly as efficient as silicon, yet the chemistry that makes them work also makes them fall apart. A film one molecule thick, modelled on the coating of a non-stick pan, now keeps one of them running at full power for 1,200 hours
【1】Solar power has become the cheapest source of new electricity, yet the material at the heart of almost every panel — highly purified silicon — remains expensive to refine, heavy to ship and too rigid to bend around a curve.That is why attention has turned to perovskites, crystalline compounds that can be printed from ink onto flexible film and whose efficiency has climbed from under 4 per cent in 2009 to 27 per cent today.
【2】The problem is that the chemistry which makes perovskites such efficient harvesters of light also makes them fragile.Under heat and illumination, ions wander through the crystal, defects multiply at its surfaces, and the layers above begin to react with it, so that the best early devices lost a fifth of their output in a few hundred hours.
【3】A study in Nature Photonics in November 2025 describes a way of closing that weakness with a film one molecule thick.It was led by Antonio Abate at the Helmholtz-Zentrum Berlin, with Guixiang Li, now a professor at Southeast University in Nanjing, as first author, and drew on partners in China, Italy, Switzerland and Germany.
【4】Their diagnosis was that the decisive damage happens not inside the perovskite but at its upper surface, where the crystal meets the electron-selective layer of carbon-60 molecules that carries charge to the electrode.That junction is studded with defects, and the C60 above it tends to clump when warm, leaving gaps through which ions escape and the metal contact can attack the crystal beneath.
【5】The team's remedy is a short molecule called sodium heptafluorobutyrate, whose head binds to exposed lead atoms while its fluorinated tail, much like a non-stick pan's coating, turns outward.Applied in solution, it settles into an almost continuous monomolecular layer.Abate describes the effect simply: it is, he says, rather like Teflon.
【6】The coating does more than repel water.It also raises the energy needed to create a defect, tunes the surface's work function so that charge leaves more readily, and induces the C60 above it to pack into a denser film that shuts off ion migration.
【7】The resulting cells reached a power-conversion efficiency of 27.02 per cent, certified at 26.96 per cent, with a one-square-centimetre device still delivering 25.95 per cent.More striking is their endurance: after 1,200 hours of continuous illumination at maximum power, they had lost none of their initial output, whereas unprotected cells shed 20 per cent in 300 hours.Aged at 85 °C for 1,800 hours they retained 92 per cent, and 94 per cent after 200 cycles between −40 °C and +85 °C.
【8】Those figures matter because the inverted architecture used here stacks naturally onto silicon, the route most manufacturers expect towards cells above 30 per cent.Yet 1,200 hours is roughly a year outdoors, not the quarter-century a commercial module must survive, and questions of lead content, scale-up and real-weather behaviour remain open.
【9】What the study really shows is that the fate of a promising material can hinge on the seams between its layers rather than on the material itself.Solar power's next leap may come less from discovering new crystals than from learning to seal the ones we already have.
原文出处：本文根据 Nature Photonics 论文《Stabilizing high-efficiency perovskite solar cells via strategic interfacial contact engineering》（Guixiang Li, Zuhong Zhang, Benjamin Agyei-Tuffour, Luyan Wu 等；通讯作者 Antonio Abate，Helmholtz-Zentrum Berlin；Nature Photonics, Vol. 20, 2026-01, pp. 55–62；线上发表 2025-11-07；DOI 10.1038/s41566-025-01791-1）及亥姆霍兹柏林中心（HZB）新闻稿公开资料改写整理，供学习使用。
三、长难句分析（三步拆解法）
Under heat and illumination, ions wander through the crystal, defects multiply at its surfaces, and the layers above begin to react with it, so that the best early devices lost a fifth of their output within a few hundred hours.
主干：三个并列分句 —— ions wander ...（离子游走）, defects multiply ...（缺陷增殖）, the layers begin to react ...（上层开始反应）
介词短语作状语：Under heat and illumination（在高温与光照下，交代三个动作发生的条件）
so that 引导结果状语从句：the best early devices lost a fifth of their output（“以至于”，说明前面三重退化的最终后果）
注意：so that 在此表“结果”而非“目的”，因为前文是已发生的事实而非意愿
考点：三项并列谓语；so that 结果状语从句；a fifth of 表分数；within + 时间段
Their diagnosis was that the decisive damage happens not inside the perovskite but at its upper surface, where the crystal meets the electron-selective layer of carbon-60 molecules that carries charge towards the electrode.
主干：Their diagnosis was that ...（主语 + 系动词 + 表语从句）
not ... but ... 并列：not inside the perovskite but at its upper surface（否定前者、肯定后者，把“体内”与“表面”对立起来）
关系副词 where 引导定语从句：where the crystal meets the electron-selective layer（修饰 upper surface，说明“表面”具体是与谁相接之处）
that 引导定语从句：that carries charge towards the electrode（修饰 layer of carbon-60 molecules，注意谓语用单数 carries，先行词是 layer）
It also raises the energy needed to create a defect, tunes the surface's electronic work function so that charge leaves more readily, and induces the C60 above it to pack into a denser film that shuts off ion migration.
主干：It raises ..., tunes ..., and induces ...（三个并列谓语，主语 It 指上文的 coating）
过去分词作后置定语：the energy needed to create a defect（“形成缺陷所需的能量”）
so that 引导目的/结果状语：so that charge leaves more readily（使电荷更容易离开）
induce sb/sth to do sth：induce the C60 to pack into a denser film（促使 C60 排列成更致密的膜）
that 引导定语从句：that shuts off ion migration（修饰 film，说明致密化的作用）
More striking is their endurance: after 1,200 hours of continuous illumination at maximum power, they had lost none of their initial output, whereas unprotected cells shed 20 per cent in 300 hours.
主干：More striking is their endurance（完全倒装：表语 + 系动词 + 主语，强调“更惊人的是耐久性”）
冒号后的解释：after 1,200 hours ..., they had lost none of their initial output（用具体数据支撑“耐久”）
过去完成时：had lost（以 1200 小时为参照点，回看此前的累计损失）
whereas 引导对比从句：unprotected cells shed 20 per cent in 300 hours（与前者形成强对比）
Yet 1,200 hours is roughly a year outdoors, not the quarter-century a commercial module must survive, and questions of lead content, scale-up and behaviour in real weather remain open.
主干：两个并列分句 —— 1,200 hours is ... a year outdoors（判断）, questions ... remain open（结论）
同位语式否定补充：not the quarter-century ...（用否定短语修正前面的“一年”，把实验室时长与商用要求并置）
省略关系词的定语从句：the quarter-century (that) a commercial module must survive（survive 此处为及物动词，“经历……而存活”）
仿写题：仿照第 8 段 "Yet 1,200 hours is roughly a year outdoors, not the quarter-century a commercial module must survive, and questions of X, Y and Z remain open."（Yet + 数据对比 + not + 更高标准 + and questions of ... remain open）的句式，为一项你熟悉的技术成果写一句“肯定成绩、同时点明局限”的评价。
