Park Hyoungmin, Jeong Seonghwa, Kim Eunsoo, Shin Sooeun, Shin Hyunjung
Department of Energy Science, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
SKKU Institute of Energy Science and Technology (SIEST), Sungkyunkwan University, Suwon 440-746, Republic of Korea.
ACS Appl Mater Interfaces. 2022 Sep 21;14(37):42007-42017. doi: 10.1021/acsami.2c10901. Epub 2022 Sep 8.
Perovskite solar cells (PSCs) have attracted tremendous interest due to their outstanding intrinsic photovoltaic properties, such as absorption coefficients, exciton binding energies, and long carrier lifetimes. Although the power conversion efficiency (PCE) of PSCs is close to the Si solar cells' PCE, device stability remains a challenge. In particular, the device stability is more critical in n-i-p normal structured PSCs, which show a higher efficiency than p-i-n inverted ones, simply because of the much lower stability of 2,2',7,7'-tetrakis[,-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spi). To prevent the devices from degrading performances arising both from perovskite's degradation and Spi instability, we prepare atomic layer deposition (ALD)-grown transition metal oxides for hole transport with efficient n-i-p PSCs. We demonstrate low-temperature ( = 45 °C)-grown amorphous ALD-VO with oxygen-deficient traps on top of Spi as an interlayer, which prevents the devices' degradation in performance. By blocking moisture and oxygen, ALD-VO was able to greatly improve the devices' stability by preserving the photovoltaic α-FAPbI phase while suppressing both Li ion diffusion from the additive and Au ions from the electrode. As a result, we successfully fabricate PSCs with passivation/hole-transporting bifunctional Spi/ALD-VO interlayers without sacrificing photovoltaic performances, and the device stability is significantly improved.
钙钛矿太阳能电池（PSCs）因其出色的本征光伏特性，如吸收系数、激子结合能和长载流子寿命，而引起了极大的关注。尽管PSCs的功率转换效率（PCE）已接近硅太阳能电池的PCE，但器件稳定性仍是一个挑战。特别是，器件稳定性在n-i-p正常结构的PSCs中更为关键，这种结构的PSCs比p-i-n倒置结构的PSCs效率更高，这仅仅是因为2,2',7,7'-四[,-二(4-甲氧基苯基)氨基]-9,9'-螺二芴（Spi）的稳定性低得多。为了防止器件因钙钛矿降解和Spi不稳定而导致性能下降，我们为高效的n-i-p PSCs制备了原子层沉积（ALD）生长的用于空穴传输的过渡金属氧化物。我们展示了在Spi顶部作为中间层生长的具有缺氧陷阱的低温（=45°C）非晶ALD-VO，它可以防止器件性能下降。通过阻挡水分和氧气，ALD-VO能够在抑制添加剂中的锂离子扩散和电极中的金离子扩散的同时，通过保留光伏α-FAPbI相来大大提高器件的稳定性。结果，我们成功制备了具有钝化/空穴传输双功能Spi/ALD-VO中间层的PSCs，且不牺牲光伏性能，器件稳定性得到显著提高。
