Chen Zihan, Li Qinghua, Chen Chuyang, Du Jiaxing, Tong Jifeng, Jin Xiao, Li Yue, Yuan Yongbiao, Qin Yuancheng, Wei Taihuei, Sun Weifu
Key Laboratory of Nondestructive Testing, Ministry of Education, Nanchang Hangkong University, Nanchang, 330063, P. R. China.
Phys Chem Chem Phys. 2014 Nov 28;16(44):24499-508. doi: 10.1039/c4cp03232b.
In this work, dysprosium ion decorated yttrium oxide (Dy(3+):Y2O3) nanocrystal phosphors were incorporated into TiO2 acceptor thin film in a bid to enhance the light harvest, charge separation and transfer in the hybrid solar cells. The results show that the energy level offset between the donor (P3HT) and the acceptor (Dy(3+):Y2O3-TiO2) has been narrowed down, thus leading to the enhanced electron and hole transports, and also photovoltaic performances as compared to pure TiO2 without incorporating Dy(3+):Y2O3. By applying femtosecond transient optical spectroscopy, after the incorporation of dopant Dy(3+):Y2O3 into TiO2 at 6 wt%, both the hot electron and hole transfer lifetimes have been shortened, that is, from 30.2 ps and 6.94 ns to 25.1 ps and 1.26 ns, respectively, and an enhanced efficiency approaching 3% was achieved as compared to 2.0% without doping, indicating that the energetic charges are captured more efficiently benefitting a higher power conversion efficiency. Moreover, these results reveal that both the conduction band (CB) and valence band (VB) edges of the acceptor were elevated by 0.57 and 0.32 eV, respectively, after incorporating 6 wt% Dy(3+):Y2O3. This work demonstrates that distinct energy level alignment engineered by Dy(3+):Y2O3 phosphor has an important role in pursuing efficient future solar cells and underscores the promising potential of rare-earth phosphor in solar applications.
在这项工作中，将镝离子修饰的氧化钇（Dy(3+):Y2O3）纳米晶荧光粉掺入二氧化钛受体薄膜中，以增强混合太阳能电池中的光捕获、电荷分离和转移。结果表明，施主（P3HT）和受体（Dy(3+):Y2O3-TiO2）之间的能级偏移已缩小，从而导致电子和空穴传输增强，与未掺入Dy(3+):Y2O3的纯二氧化钛相比，光伏性能也得到提高。通过应用飞秒瞬态光谱，在将掺杂剂Dy(3+):Y2O3以6 wt%掺入二氧化钛后，热电子和空穴转移寿命均缩短，即分别从30.2 ps和6.94 ns缩短至25.1 ps和1.26 ns，与未掺杂时的2.0%相比，实现了接近3%的更高效率，表明高能电荷被更有效地捕获，有利于提高功率转换效率。此外，这些结果表明，在掺入6 wt% Dy(3+):Y2O3后，受体的导带（CB）和价带（VB）边缘分别升高了0.57和0.32 eV。这项工作表明，Dy(3+):Y2O3荧光粉设计的独特能级排列在追求高效未来太阳能电池方面具有重要作用，并强调了稀土荧光粉在太阳能应用中的广阔前景。
