http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Zhitomirsky, David (검색결과 2 건)
- 무료
- 기관 내 무료
- 유료
-
Synergistic photocurrent addition in hybrid quantum dot: Bulk heterojunction solar cells
Kim, Gi-Hwan,Walker, Bright,Zhitomirsky, David,Heo, Jungwoo,Ko, Seo-Jin,Park, Jongnam,Sargent, Edward H.,Young Kim, Jin Elsevier 2015 Nano energy Vol.13 No.-
<P><B>Abstract</B></P> <P>We investigate the effect of a thin PbS quantum dot (QD) layer on the performance of hybrid quantum-dot-organic solar cells (QD-OSCs). The PbS QD layer is able to function as a photosensitizing layer to improve short circuit current density (<I>J</I> <SUB>SC</SUB>) and power conversion efficiency (PCE) by exploiting solar flux in the near infrared region up to 1100nm. The increase in <I>J</I> <SUB>SC</SUB> is well represented by changes observed in the external quantum efficiency of devices with and without the PbS QD layer, including the region of the first exciton transition where only the PbS QD layer absorbs. Remarkably, enhanced performance was observed in QD-OSCs consisting of just a 13nm thick PbS QD layer and 150nm PTB7:PC<SUB>71</SUB>BM layer, exhibiting a <I>J</I> <SUB>SC</SUB> of 17.0mAcm<SUP>−2</SUP>, and PCE of 8.30% (8.58% for champion device) compared to reference devices without PbS QD which produced a <I>J</I> <SUB>SC</SUB> of 15.4mAcm<SUP>−2</SUP> and PCE of 7.56%.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We have fabricated hybrid solar cells using a PbS QD layer and PTB7/PC<SUB>71</SUB>BM layer. </LI> <LI> The device is built on PTB7:PC<SUB>71</SUB>BM bulk heterojunction and a PbS QD layer. </LI> <LI> The PbS QD layer acts as a photosensitizing layer to improve the device performance. </LI> <LI> Additional photocurrent leads to enhancement in performance in hybrid solar cells. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>The effect of a thin PbS quantum dot (QD) layer on the performance of hybrid quantum-dot-organic solar cells (QD-OSCs) was investigated. The PbS QD layer is able to function as a photosensitizing layer with PTB7/PC<SUB>71</SUB>BM bulk heterojunction to improve short circuit current density from 15.4mAcm<SUP>−2</SUP> to 17.0mAcm<SUP>−2</SUP> and power conversion efficiency from 7.56% to 8.30%. </P> <P>[DISPLAY OMISSION]</P>
-
Origins of the Stokes Shift in PbS Quantum Dots: Impact of Polydispersity, Ligands, and Defects
Liu, Yun,Kim, Donghun,Morris, Owen P.,Zhitomirsky, David,Grossman, Jeffrey C. American Chemical Society 2018 ACS NANO Vol.12 No.3
<P>Understanding the origins of the excessive Stokes shift in the lead chalcogenides family of colloidal quantum dots (CQDs) is of great importance at both the fundamental and applied levels; however, our current understanding is far from satisfactory. Here, utilizing a combination of <I>ab initio</I> computations and UV-vis and photoluminescence measurements, we investigated the contributions to the Stokes shift from polydispersity, ligands, and defects in PbS CQDs. The key results are as follows: (1) The size and energetic disorder of a polydisperse CQD film increase the Stokes shift by 20 to 50 meV compared to that of an isolated CQD; (2) Franck-Condon (FC) shifts increase as the electronegativities of the ligands increase, but the variations are small (<15 meV). (3) Unlike the aforementioned two minor factors, the presence of certain intrinsic defects such as V<SUB>Cl</SUB><SUP>+</SUP> (in Cl-passivated CQDs) can cause substantial electron density localization of the band edge states and consequent large FC shifts (100s of meV). This effect arising from defects can explain the excessive Stokes shifts in PbS CQDs and improve our understanding of the optical properties of PbS CQDs.</P> [FIG OMISSION]</BR>
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
