Photovoltaic Properties of Organic Photoactive Particle Dispersions

Dang

Grant

et al. 2014

Previous studies have shown that the use of bis(tri-n-hexylsilyl oxide) silicon phthalocyanine ((3HS)2-SiPc) as an additive in a P3HT:PC61BM cascade ternary bulk heterojunction organic photovoltaic (BHJ OPV) device results in an increase in the short circuit current (J(SC)) and efficiency (η(eff)) of up to 25% and 20%, respectively. The previous studies have attributed the increase in performance to the presence of (3HS)2-SiPc at the BHJ interface. In this study, we explored the molecular characteristics of (3HS)2-SiPc which makes it so effective in increasing the OPV device J(SC) and η(eff. Initially, we synthesized phthalocyanine-based additives using different core elements such as germanium and boron instead of silicon, each having similar frontier orbital energies compared to (3HS)2-SiPc and tested their effect on BHJ OPV device performance. We observed that addition of bis(tri-n-hexylsilyl oxide) germanium phthalocyanine ((3HS)2-GePc) or tri-n-hexylsilyl oxide boron subphthalocyanine (3HS-BsubPc) resulted in a nonstatistically significant increase in JSC and η(eff). Secondly, we kept the silicon phthalocyanine core and substituted the tri-n-hexylsilyl solubilizing groups with pentadecyl phenoxy groups and tested the resulting dye in a BHJ OPV. While an increase in JSC and η(eff) was observed at low (PDP)2-SiPc loadings, the increase was not as significant as (3HS)2-SiPc; therefore, (3HS)2-SiPc is a unique additive. During our study, we observed that (3HS)2-SiPc had an extraordinary tendency to crystallize compared to the other compounds in this study and our general experience. On the basis of this observation, we have offered a hypothesis that when (3HS)2-SiPc migrates to the P3HT:PC61BM interface the reason for its unique performance is not solely due to its frontier orbital energies but also might be due to a high driving force for crystallization.

Section: ■ Results and Discussionmentioning

confidence: 89%

Section: Results and Discussionmentioning

confidence: 99%

Bis(tri-n-hexylsilyl oxide) Silicon Phthalocyanine: A Unique Additive in Ternary Bulk Heterojunction Organic Photovoltaic Devices

Dang

Grant

et al. 2014

“…31 Although the cell characteristics were poor by modern standards, their results did however indicate that silicon and germanium containing Pcs could potentially be used in OPV devices. 31 Thereafter, Xerox Corporation developed a patent position on the use of GePcs in xerographic organic photoreceptors. 32−36 Since then, very few examples can be found in the literature employing SiPc or GePc in an organic electronic device.…”

Section: ■ Introductionmentioning

confidence: 99%

“…In the early 1980s, Loutfy and co-workers explored the use of dichloro silicon and dichloro germanium phthalocyanines (Cl 2 -SiPc and Cl 2 -GePc, respectively, Figure ) and their respective dihydroxy-MPc derivatives in a single active layer OPV devices . Although the cell characteristics were poor by modern standards, their results did however indicate that silicon and germanium containing Pcs could potentially be used in OPV devices . Thereafter, Xerox Corporation developed a patent position on the use of GePcs in xerographic organic photoreceptors. − Since then, very few examples can be found in the literature employing SiPc or GePc in an organic electronic device.…”

Section: Introductionmentioning

confidence: 99%

Assessing the Potential Roles of Silicon and Germanium Phthalocyanines in Planar Heterojunction Organic Photovoltaic Devices and How Pentafluoro Phenoxylation Can Enhance π–π Interactions and Device Performance

White

AL-Amar

et al. 2015

107

In this study, we have assessed the potential application of dichloro silicon phthalocyanine (Cl2-SiPc) and dichloro germanium phthalocyanine (Cl2-GePc) in modern planar heterojunction organic photovoltaic (PHJ OPV) devices. We have determined that Cl2-SiPc can act as an electron donating material when paired with C60 and that Cl2-SiPc or Cl2-GePc can also act as an electron acceptor material when paired with pentacene. These two materials enabled the harvesting of triplet energy resulting from the singlet fission process in pentacene. However, contributions to the generation of photocurrent were observed for Cl2-SiPc with no evidence of photocurrent contribution from Cl2-GePc. The result of our initial assessment established the potential for the application of SiPc and GePc in PHJ OPV devices. Thereafter, bis(pentafluoro phenoxy) silicon phthalocyanine (F10-SiPc) and bis(pentafluoro phenoxy) germanium phthalocyanine (F10-GePc) were synthesized and characterized. During thermal processing, it was discovered that F10-SiPc and F10-GePc underwent a reaction forming small amounts of difluoro SiPc (F2-SiPc) and difluoro GePc (F2-GePc). This undesirable reaction could be circumvented for F10-SiPc but not for F10-GePc. Using single crystal X-ray diffraction, it was determined that F10-SiPc has significantly enhanced π-π interactions compared with that of Cl2-SiPc, which had little to none. Unoptimized PHJ OPV devices based on F10-SiPc were fabricated and directly compared to those constructed from Cl2-SiPc, and in all cases, PHJ OPV devices based on F10-SiPc had significantly improved device characteristics compared to Cl2-SiPc.

“…39,40 In 1983 R 2 −SiPc derivatives made their first appearance in single layer OPVs with basic electrical characterization. 41 Fastforward to 2009 where Honda et al demonstrated that 24 (3HS−SiPc) can act as an effective ternary additive in a poly(3hexylthiophene):phenyl-C 61 -butyric acid methyl ester (P3HT:PC 61 BM) bulk heterojunction (BHJ) OPV device providing 20% increase in PCE due to the increased J SC from the additional absorption of the R 2 −SiPc at 685 nm. 42 Compound 24 is effective at low loadings (<10 wt %) because it migrates to the P3HT:PC 61 BM interface, facilitating the cascade energy transfer.…”

Section: Sipc Based Opvsmentioning

confidence: 99%

The Rise of Silicon Phthalocyanine: From Organic Photovoltaics to Organic Thin Film Transistors

2021

Silicon phthalocyanines are emerging n-type semiconductors for use in organic photovoltaics (OPVs) and organic thin-film transistors (OTFTs). Their low synthetic complexity paired with their versatile axial group facilitates the fine-tuning of their chemical properties, solution properties and processing characteristics without significantly affecting their frontier orbital levels or their absorption properties. The crystal engineering and film forming characteristics of silicon phthalocyanine semiconductors can be tuned through appropriate axial group functionalization, therefore facilitating their integration into both OTFTs and OPVs by solution processing or vapor deposition. This Spotlight on Applications will discuss recent advances in the integration of this exciting class of phthalocyanine into OTFTs and OPVs and highlights their promising future.