A Highly Conductive Titanium Oxynitride Electron‐Selective Contact for Efficient Photovoltaic Devices

Yang, Xinbo; Lin, Yuanbao; Liu, Jiang; Liu, Wenzhu; Bi, Qunyu; Song, Xin; Kang, Jingxuan; Xu, Fuzong; Xu, Lujia; Hedhili, Mohamed N.; Baran, Derya; Zhang, Xiaohong; Anthopoulos, Thomas D.; Wolf, Stefaan De

doi:10.1002/adma.202002608

Cited by 62 publications

(74 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…To achieve high-performance surface passivation, a-Si:H(i) passivating layer with optimized thickness of about 6 nm is deposited on the c-Si surface. [6,10,38] Figure 1c shows the effective minority carrier lifetime of symmetrically structured a-Si:H(i)/c-Si/a-Si:H(i) and CsX/a-Si:H(i)/c-Si/a-Si:H(i)/CsX contacts. After depositing thin a-Si:H(i) passivating layers (%6 nm) on the both sides, well-passivated interface with a low effective surface recombination velocity (S eff ) of about 3.9 cm s À1 is achieved.…”

Section: Resultsmentioning

confidence: 99%

“…For example, some metal oxides (e.g., titanium oxide, magnesium oxide, and tantalum oxide) and metal nitrides (e.g., titanium nitride, titanium oxynitride, and tantalum nitride) can form effective electron-selective contacts with n-type c-Si even if they do not have low work function. [30][31][32][33][34][35][36][37][38] This is mainly attributed to the thin silicon oxide (SiO x ) layers formed during the deposition processes, which can produce effective passivation on c-Si surface. Although high PCEs about 20% have been reported using these ETLs in c-Si solar cells, there is still room for further improvement.…”

Section: Doi: 101002/solr202000569mentioning

confidence: 99%

See 1 more Smart Citation

Solution‐Processed Electron‐Selective Contacts Enabling 21.8% Efficiency Crystalline Silicon Solar Cells

Wang

Cai

et al. 2020

Solar RRL

View full text Add to dashboard Cite

Crystalline silicon (c‐Si) solar cells with carrier‐selective passivating contacts have been prosperously developed over the past few years, showing fundamental advantages, e.g., simpler configurations and higher potential efficiencies, compared with conventional c‐Si solar cells using highly doped emitters. Herein, solution‐processed cesium halides (CsX, X represents F, Cl, Br, I) are investigated as electron‐selective contacts for c‐Si solar cells, enabling lowest contact resistivity down to about 1 mΩ cm2 for slightly doped n‐type c‐Si/CsF/Al contact. After inserting a thin intrinsic amorphous silicon (a‐Si:H(i)) passivating layer, the contact resistivity can still be kept in a low value, about 10 mΩ cm2. With full area rear‐side a‐Si:H(i)/CsF/Al electron‐selective passivating contacts, record power conversion efficiencies of about 21.8% are finally demonstrated for n‐type c‐Si solar cells, showing a simple approach to realize high‐efficiency c‐Si solar cells.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Doi: 101002/solr202000569mentioning

confidence: 99%

Solution‐Processed Electron‐Selective Contacts Enabling 21.8% Efficiency Crystalline Silicon Solar Cells

Wang

Cai

et al. 2020

Solar RRL

View full text Add to dashboard Cite

show abstract

“…[24,25] This layer can also enhance carrier extraction out of silicon if the work function is suitable. [26,27] Here, an extra layer between silicon and rear electrode, for instance, MoO 3-x layer, has been used to passivate silicon rear surface and extract carriers (as illustrated in Figure 4a,b). [28,29] The peak output voltage of the device with the MoO 3-x interlayer is two times higher than that of the device without an interlayer, yielding a value of approximately 900 mV.…”

Section: Interfacial Effects On Friction-induced Carriersmentioning

confidence: 99%

Simultaneously Harvesting Friction and Solar Energy via Organic/Silicon Heterojunction with High Direct‐Current Generation

Wang

Guo-hua

et al. 2021

Advanced Energy Materials

View full text Add to dashboard Cite

two materials that are mainly insulators or metals. To harvest mechanical energy, displacement current is generated through modulating the contact area or distance of two materials, resulting in alternating dielectric displacement current outputs. [8] According to the electrodynamics theory, the high output voltage of conventional TENGs is due to charge accumulation at the material surface, for example, polymers. However, the low conductivity of the polymer itself results in large device impedance, leading to the poor current generation capability of polymer-based TENGs (in the order of 0.01-0.1 A m −2 ). [9] Alternative materials and structures are highly indispensable to enhance device performance. Recently, a new TENG structure has been proposed based on semiconductor dynamic contacts, which generates high-density direct-current (d. c.) without any rectifier module. [10][11][12][13][14] "Tribovoltaic effect," as similar as the photovoltaic effect of semiconductors, has been proposed to interpret the working mechanism, which points out that charge carriers are induced at the interface during friction and then collected by two electrodes separately. [15] This concept has emphasized the significance of carrier generation and transport in semiconductor-based TENGs, indicating crucial roles of interfacial properties that dominate the device performance.Silicon is one of the most successful semiconductors widely used in microelectronic products and photoelectronic devices taking advantage of its outstanding charge carrier transport properties. Silicon-based TENGs were proposed to realize high current density and rectification-free d. c. portable power sources. The thickness of the oxide layer on the silicon surface is the key factor that could influence the performance of these TENGs. The short-circuit current density of 1-10 A m −2 and the open-circuit voltage of 300-400 mV were achieved by moving a metal tip on p-type silicon with a native oxide layer. [16] Moreover, the current density of silicon-based TENGs could be further improved to approximately 40 A m −2 by replacing metal tip with graphene film. [17] However, the output voltage of the graphene/ Si TENGs dramatically shrunk to only approximately 200 mV. According to the conductive-atomic force microscope (c-AFM) experiments, the theoretical output current of metal/Si dynamic contacts could reach 10 4 A m −2 , [16] indicating the huge potential of further improvement on the device current generation. ForThe direct-current triboelectric nanogenerator (TENG) is a promising portable energy source that can power mobile electronics without any rectification circuits. Recently, the silicon-based TENGs, as a rectification-free power source, have drawn wide attention due to their high current-density outputs. However, the performance of silicon-based TENGs is still inferior owing to a low amount of carrier generation and poor efficiency of carrier collection. Here, a strategy is proposed to improve the performance of metal/ silicon TENGs via building an alternative ...

show abstract

“…Therefore, extensive efforts have been devoted to the improvement of silicon solar cells with dopant‐free passivating contacts. [ 4–9 ] By replacing a‐Si:H(p) with a 4 nm thick hole‐collecting and transparent molybdenum oxide (MoO x ) layer, a remarkable solar cell efficiency of 23.5% was recently demonstrated. [ 10 ] The integration of an a‐Si:H(i)/LiF x /Al electron selective contact at the rear side, instead of a‐Si:H(i)/ a‐Si:H(n)/ITO/Ag, [ 11 ] enabled the development of a fully dopant‐free silicon solar cell without any doped a‐Si:H layers or diffused p–n junctions.…”

Section: Introductionmentioning

confidence: 99%

“…[ 12,30 ] In that case, the contact resistance is potentially low to form a partial‐area heterocontact for dopant‐free bifacial silicon solar cells with a metal contact fraction between 10% and 50%. [ 31 ] In contrast to most electron transporting layers (0.5–10 nm), [ 6,9,13,20–24,27,32–34 ] a thick ZnO (60–140 nm) electron‐selective layer can additionally serve as a transparent antireflective coating (ARC), thus simplifying the fabrication process.…”

Section: Introductionmentioning

confidence: 99%

Dopant‐Free Bifacial Silicon Solar Cells

et al. 2021

View full text Add to dashboard Cite

Herein, challenges in the fabrication of full dopant‐free bifacial silicon solar cells are discussed and efficient devices utilizing a MoO3/ indium tin oxide (ITO)/Ag hole‐selective contact and ZnO/LiFx/Al electron‐selective contacts with up to 79% short‐circuit current bifaciality are demonstrated. The ZnO/LiFx/Al rear electron contact features a full‐area ZnO antireflective coating and a LiFx/Al finger contact, allowing sunlight absorption from the back side, thus producing more overall power. The ZnO/LiFx/Al electron contacts with a thinner ZnO layer and a larger contact fraction display a better selectivity and a lower resistance loss. When considering rear‐side irradiance of 0.15 sun, the dopant‐free bifacial solar cell with 60 nm ZnO and 50% LiFx/Al metal contact fraction achieves a 3% estimated output power density improvement compared with its monofacial counterpart (21.0 mW cm−2 compared to 20.3 mW cm−2) using the full‐area back contact. Both the efficiency and bifaciality factor of this dopant‐free device are still significantly lower than those of state‐of‐the‐art devices relying on doped‐silicon‐based layers. The required improvement for this technology to become industry‐relevant is discussed.

show abstract

A Highly Conductive Titanium Oxynitride Electron‐Selective Contact for Efficient Photovoltaic Devices

Cited by 62 publications

References 47 publications

Solution‐Processed Electron‐Selective Contacts Enabling 21.8% Efficiency Crystalline Silicon Solar Cells

Solution‐Processed Electron‐Selective Contacts Enabling 21.8% Efficiency Crystalline Silicon Solar Cells

Simultaneously Harvesting Friction and Solar Energy via Organic/Silicon Heterojunction with High Direct‐Current Generation

Dopant‐Free Bifacial Silicon Solar Cells

Contact Info

Product

Resources

About