High Efficiency Quantum Dot Heterojunction Solar Cell Using Anatase (001) TiO2 Nanosheets
High Efficiency Quantum Dot Heterojunction Solar Cell Using Anatase (001) TiO2 Nanosheets
复制标题
DOI：
10.1002/adma.201104497
复制
发表时间：
2012-04-24
影响因子：
29.4
通讯作者：
Graetzel, Michael
中科院分区：
文献类型：
--
作者：
Etgar, Lioz;Zhang, Wei;Graetzel, Michael
量子点由于其可调谐的带隙和高的光吸收截面而引起了人们的广泛关注。[1-3]各种研究项目试图将量子点集成到太阳能电池器件中，包括纳米（NC）-聚合物混合太阳能电池、NC-肖特基太阳能电池、NC-敏化二氧化钛（TiO 2）太阳能电池和NC混合双层太阳能电池。[4-12]最近的研究集中在QD异质结太阳能电池上，通过在QD和FTO之间放置氧化物NC（TiO 2或ZnO）作为薄间隔层。[13-19]此外，还展示了具有相同结构的叠层量子点太阳能电池。[20]在类似的基于QD的太阳能电池结构中也证明了多激子产生（MEG）效应。[21]PbS和PbSe QD属于IV-VI族，已知其在可见光和近红外区域中的高吸收率。它们具有相对较大的玻尔半径，[22-24]较大的基态吸收截面（约10-15 cm− 2）和较长的激子寿命（约200-800 ns）。[25]此外，它们的禁带宽度可在0.3- 2.0eV之间调节。理论上，TiO_2的晶体结构可构造为具有8个等效（101）晶面和上下两个等效（001）晶面的截顶八面体。[26]研究表明，TiO_2的（001）晶面比（101）晶面具有更高的反应活性，而（101）晶面具有更高的热稳定性。[27]此外，（101）晶面的带边比（001）晶面的带边更负. [28日]
Quantum dots (QDs) have attracted a lot of attention due to their tunable bandgap and their high optical absorption cross section.[1–3] A variety of research projects attempt to integrate QDs into solar cells devices, including nanocrystal (NC)-poly mer hybrid solar cells, NC-Schottky solar cells, NC-sensitized titanium dioxide (TiO 2) solar cells, and NC hybrid bilayer solar cells.[4–12] Recently investigations focus on QD heterojunction solar cells, by placing oxide NCs (TiO 2 or ZnO) as a thin spacer layer between the QDs and the FTO.[13–19] In addition, a tandem QD solar cell with the same structure has been demonstrated as well.[20] Multiple exciton generation (MEG) effect was also demonstrate in similar QD based solar cell structure.[21]PbS and PbSe QDs belong to group IV-VI, which are known for their high absorbance in the visible and in the near infrared regions. They have a relatively large Bohr radius,[22–24] large ground state cross section of absorption (∼ 10–15 cm− 2) and long excitonic lifetime (∼ 200–800 ns).[25] In addition their bandgap can be tuned between 0.3–2.0 eV The crystal structure of anatase TiO 2 can be theoretically constructed as truncated octahedron with eight equivalent (101) facets and two equivalent (001) facets on the top/bottom.[26] Studies have shown that the (001) facets of anatase TiO 2 are more reactive than the (101) facets which are more thermodynamically stable.[27] Moreover, the band edge of anatase TiO 2 with dominant (101) facets is more negative than the exposed (001) anatase TiO 2.[28]