两步沉积法制备锡基钙钛矿及其全溶液工艺太阳能电池性能

两步沉积法中胺盐的传统溶剂异丙醇会对锡基钙钛矿产生严重破坏,因此探索其他溶剂制备锡基钙钛矿非常重要。利用4-甲基-2-戊醇取代异丙醇充当胺盐的溶剂,并在胺盐中添加苯乙基溴化胺(PEABr),通过两步沉积法制备了锡基钙钛矿薄膜及全溶液工艺太阳能电池。实验结果表明,相比于异丙醇,使用4-甲基-2-戊醇作为胺盐溶剂,可降低对锡基钙钛矿的破坏作用,促进锡基钙钛矿结晶成膜,原因可能是该溶剂分子的烷基部分可以增加对羟基的空间位阻。但未添加PEABr时,制备的FASnI₃薄膜存在许多针孔,器件光电转换效率(PCE)仅为0.24%;在添加摩尔占比为0.3 (n (PEABr)/n (FAI+PEABr)=0.3)的PEABr时,制备的锡基钙钛矿薄膜针孔减少,致密度提高,表面形貌得到改善。利用全溶液工艺制备的基于该薄膜的太阳能电池PCE达到4.15%。该研究有助于促进两步沉积法制备锡基钙钛矿薄膜及其光伏器件的进一步发展。     

电极用金属的功函数对OLED发光性能的影响

OLED是一种主动发光器件，影响器件发光性能的因素很多，如电子流与空穴流间的平衡、发光层内电子与空穴的有效复合、外部注入非平衡载流子的能力等。外部注入非平衡载波子的能力与金属－半导体的界面特性有关。本文基于热电子发射理论论述了电极用金属的功函数与非平衡载流子注入的关系，说明其对OLED发光性能的影响。     

基于P3HT的无铅钙钛矿太阳能电池性能仿真研究

综合考虑无毒、价廉等因素,设计以P3HT为空穴传输层的锡基钙钛矿太阳能电池。以太阳能电池模拟软件SCAPS-1D对结构为TCO/Ti O_2/CH_3NH_3Sn I_3/P3HT/Au的太阳能电池进行数值模拟仿真,探讨吸收层、电子传输层和空穴传输层的厚度和掺杂浓度,以及吸收层缺陷态密度对电池性能的影响。由仿真结果可知,当吸收层、电子传输层和空穴传输层的厚度分别为140、20以及200 nm,掺杂浓度分别为1×10~(16)cm~(-3)、1×10~(16)cm~(-3)和1×10~(17)cm~(-3),吸收层缺陷态密度为1×10~(16)cm~(-3)时,取得了较佳的结果:V_(oc)=0.77 V,J_(sc)=20.48 m A/cm~2,FF=71.58%,PCE=11.27%。     

不同p电极下InGaN太阳能电池性能研究

利用MOCVD方法在蓝宝石衬底上生长InGaN量子阱结构太阳能电池,并制作出了不同间距和形状的指叉形状p型电极。通过实验对比发现,随着指叉间距的减小,电极面积增加,光吸收面积减小,从而减少了光电流的产生,使得电池效率退化。另据实验发现,由于器件MESA边缘有着更强的电场,相同指叉密度下,将电极制作在器件边缘可取得更好的电池性能。     

表/界面双重修饰提高钙钛矿太阳能电池性能

采用二维/三维(2D/3D)钙钛矿结构已被证明是提高钙钛矿太阳能电池综合性能的有效策略,但该策略通常要求表面2D修饰层厚度极薄致使其不能连续覆盖3D钙钛矿层,而未覆盖/修饰的3D钙钛矿表/界面则可能因仍然存在大量缺陷而影响器件性能。基于此,研发了一种简单有效的环己甲胺氢碘酸盐(CMI)+苯乙基碘化铵(PEAI)表/界面双重修饰策略,即利用PEAI修饰由CMI构建的2D/3D钙钛矿结构来实现更为充分的缺陷钝化和界面修饰。结果表明,CMI+PEAI双重修饰钙钛矿薄膜的表面粗糙度和缺陷态密度明显低于未处理和单一CMI表界面修饰的钙钛矿薄膜,分别降至11.3 nm和2.29×1015 cm-3,且该双重修饰方法将钙钛矿薄膜的光生载流子寿命提高至45.1 ns,并有效促进了钙钛矿/空穴传输界面处的电荷提取,最终使太阳能电池的性能参数得到明显提升。CMI+PEAI双重修饰太阳能电池的平均能量转化效率为20.12%±0.35%,明显优于未处理器件(16.79%±0.57%)及单一CMI表/界面修饰器件(18.81%±0.34%),同时也展现出了最佳稳定性。该研究提供了一种更为充分、有效的钙钛矿表界面...     

银铝锡欧姆接触易焊电极浆料的研制

采用还原性强的贱金属铝和锡与贵金属银按一定的配比组合，选乙基纤维素－松油醇体系有机载体，硼硅铅易熔玻璃体及微量氧化物组成混合电极。在４８０～７００℃温度范围，能与ＰＴＣＲ钛酸钡陶瓷形成良好的欧姆接触，最佳烧成温度为５２０～５５０℃，电极与瓷体附着良好，容易焊接，可实现ＰＴＣＲ陶瓷电极一次涂覆，克服了复合电极成本高，工艺复杂等缺点。     

纤维素对光伏电池电极铝浆流变性能的影响

研究了太阳能电池铝电极浆料中乙基纤维素(EC)的相对分子质量对浆料流变特性的影响,对比了含有不同相对分子质量的EC的铝浆的丝网印刷效果。结果表明,随着EC相对分子质量的增大,一方面,浆料的触变性大幅度提高,高剪切速率下的黏度下降,有利于丝网印刷时浆料通过网孔;另一方面,印刷线条高宽比逐渐提高,线条断面形状趋于矩形。由此可见含有相对分子质量较大的EC的铝浆的流变性能更满足太阳能电池电极的高精度印刷要求,有利于太阳能电池效率的提高。     

InP基转移电子器件接触性能的优化研究

The effect of the annealing time and annealing temperature on Ni/Ge/Au electrode contacts deposited on the n-type InP contact layer has been studied using a circular transmission line model. The minimum specific contact resistance of 3.210 7 cm2was achieved on the low-doped n-type InP contact layer with a 40 s anneal at 425 ℃. In order to improve the ohmic contact and reduce the difficulty in the fabrication of the high doped InP epi-layer, the doping concentration in the InP contact layer was chosen to be 51018cm 3in the fabrication of transferred electronic devices. Excellent differential negative resistance properties were obtained by an electron beam evaporating the Ni/Ge/Au/Ge/Ni/Au composite electrode on an InP epi-layer with a 60 s anneal at 380 ℃.     

氧化对 GaN 基LED透明电极接触特性的影响

研究了热退火对InGaN/GaN 多量子阱LED的Ni/Au-p-GaN欧姆接触的影响.发现在空气和 N2气氛中交替地进行热退火的过程中Ni/Au接触特性显示出可逆现象. Ni/Au-p-GaN接触的串联电阻在空气中随合金化时间逐渐减小,在随后的 N2 中的热退火后会使该串联电阻增加,但在空气中再次热退火能使接触特性得到恢复.同时对Ni/Au-p-GaN 接触在空气中合金化过程中的层反转的成因进行了讨论.     

Efficient Inverted Perovskite Solar Cells with a Fill Factor Over 86% via Surface Modification of the Nickel Oxide Hole Contact

The poor interface quality between nickel oxide (NiO_x) and halide perovskites limits the performance and stability of NiO_x-based perovskite solar cells (PSCs). Here a reactive surface modification approach based on the in situ decomposition of urea on the NiO_x surface is reported. The pyrolysis of urea can reduce the high-valence state of nickel and replace the adsorbed hydroxyl group with isocyanate. Combining theoretical and experimental analyses, the treated NiO_x films present suppressed surface states and improved transport energy level alignment with the halide perovskite absorber. With this strategy, NiO_x-based PSCs achieve a champion power conversion efficiency (PCE) of 23.61% and a fill factor of over 86%. The device's efficiency remains above 90% after 2000 h of thermal aging at 85 °C. Furthermore, perovskite solar modules achieve PCE values of 18.97% and 17.18% for areas of 16 and 196 cm², respectively.     

High‐Performance Inverted Planar Heterojunction Perovskite Solar Cells Based on Lead Acetate Precursor with Efficiency Exceeding 18%

Organic–inorganic lead halide perovskites are emerging materials for the next‐generation photovoltaics. Lead halides are the most commonly used lead precursors for perovskite active layers. Recently, lead acetate (Pb(Ac)₂) has shown its superiority as the potential replacement for traditional lead halides. Here, we demonstrate a strategy to improve the efficiency for the perovskite solar cell based on lead acetate precursor. We utilized methylammonium bromide as an additive in the Pb(Ac)₂ and methylammonium iodide precursor solution, resulting in uniform, compact and pinhole‐free perovskite films. We observed enhanced charge carrier extraction between the perovskite layer and charge collection layers and delivered a champion power conversion efficiency of 18.3% with a stabilized output efficiency of 17.6% at the maximum power point. The optimized devices also exhibited negligible current density–voltage (J–V) hysteresis under the scanning conditions.     

Pre-buried Interface Strategy for Stable Inverted Perovskite Solar Cells Based on Ordered Nucleation Crystallization

The buried interface has important effect on carrier extraction and nonradiative recombination of perovksite solar cells (PSCs). Herein, to inactivate the buried interfacial defects of perovskite and boost the crystallization quality of perovskite film, 3-amino-1-adamantanol (AAD) serves as a pre-buried interface modifier on nickel oxide (NiO_x) surface to regulate the nucleation and crystallization process of perovskite precursor. The amino and hydroxyl groups in AAD molecule can synchronously coordinate with nickel ion (Ni³⁺) in NiO_x and lead ion in perovskite, respectively. The dual action favors the ordered arrangement of AAD molecules between NiO_x and perovskite, which not only enhances hole extraction in hole transport layer, but also provides active sites for homogeneous nucleation. Furthermore, AAD modifier blocks the unfavorable reaction between Ni³⁺ and perovskite, and effectively passivates the buried interfacial defects. The optimal inverted PSCs achieve a champion power conversion efficiency of 22.21% with negligible hysteresis, favorable thermal, optical, and long-term stability. Thus, this strategy of modulating perovskite nucleation and crystallization by pre-buried modifier is feasible for achieving efficient and stable inverted perovskite solar cells.     

Imide-Functionalized Triarylamine-Based Donor-Acceptor Polymers as Hole Transporting Layers for High-Performance Inverted Perovskite Solar Cells

Dopant-free hole-transporting layers (HTLs) are highly desired for realizing efficient and stable perovskite solar cells (PVSCs), but only very few of them can enable power conversion efficiencies (PCEs) over 20%. Herein, two imide-functionalized triarylamine-based donor-acceptor (D-A) type copolymers, PBTI-TPA and PTTI-TPA, are developed and applied as dopant-free HTLs in inverted PVSCs. The combination of a classic redox-active triphenylamine donor unit and an electron-withdrawing oligothiophene imide co-unit with rigid and planar backbone furnishes the two polymers with quasi-planar backbone, suitable frontier molecular orbital (FMO) energy levels, favorable thermal stability, appropriate film morphology, and passivation effect. More importantly, the greatly improved hole mobility renders them as promising HTLs for PVSCs. As a result, the undoped PTTI-TPA-based inverted PVSCs deliver a remarkable PCE up to 21% as well as negligible hysteresis and substantial long-term stability, outperforming the devices based on PBTI-TPA and PTAA. The performance also represents one of the highest PCEs reported to date for PVSCs based on dopant-free polymeric HTLs. The results highlight the great potentials of oligothiophene imides for constructing donor-acceptor polymeric HTLs for enabling high-performance dopant-free PVSCs.     

Samarium-Doped Nickel Oxide for Superior Inverted Perovskite Solar Cells: Insight into Doping Effect for Electronic Applications

Hole transport layers (HTLs) play a key role in perovskite solar cells (PSCs), particularly in the inverted PSCs (IPSCs) that demand more in its stability. In this study, samarium-doped nickel oxide (Sm:NiO_x) nanoparticles are synthesized via a chemical precipitation method and deposited as a hole transport layer in the IPSCs. Sm³⁺ doping can reduce the formation energy of Ni vacancy and naturally increase the density of Ni vacancies, thereby rendering increased hole density. Thenceforth, the electronic conductivity is enhanced significantly, and work function enlarged in the Sm:NiO_x film in favor of extracting holes and suppressing charge recombination. Consequently, the Sm:NiO_x-based IPSCs attain outstanding power conversion efficiencies as high as 20.71%. Even when it is applied in flexible solar cells, it still outputs efficiency as high as 17.95%. More importantly, the Sm:NiO_x is compatible with large-scale processing whereby the large area IPSCs of 1.0 cm² and 40 × 40 mm² deliver high efficiencies of 18.51% and 15.27%, respectively, all are among the highest for the inorganic HTLs based IPSCs. This research demonstrates that, while revealing the doping effect in depth, Sm:NiO_x can be a promising hole transport material for fabricating efficient, large-area, and flexible IPSCs in the future.     

Overcoming the PCBM/Ag Interface Issues in Inverted Perovskite Solar Cells by Rhodamine-Functionalized Dodecahydro-Closo-Dodecaborate Derivate Interlayer

Efficient modification of the interface between metal cathode and electron transport layer are critical for achieving high performance and stability of the inverted perovskite solar cells (PSCs). Herein, a new alcohol-soluble rhodamine-functionalized dodecahydro-closo-dodecaborate derivate, RBH, is developed and applied as an efficient cathode interlayer to overcome the (6,6)-phenyl-C₆₁ butyrie acid methyl ester (PCBM)/Ag interface issues. By introducing RBH cathode interlayer, the functions of the interface traps passivation, interfacial hydrophobicity enhancement, interface contact improvement as well as built-in potential enhancement are realized at the same time and thus correspondingly improve the device performance and stability. Consequently, a power conversion efficiency (PCE) of 21.08% and high fill factor of 83.37% are achieved, which is one of the highest values based on solution-processed MAPbI₃/PCBM heterojunction PSCs. Moreover, RBH can act as a shielding layer to slow down moisture erosion and self-corrosion. The PCE of the RBH devices still maintain 84% for 456 h (85 °C @ N₂), 87% for 360 h (23 °C @ relative humidity (RH) 35%) of its initial PCE value, while the control device can only maintain ≈23%, 58% of its initial PCE value under the same exposure conditions, respectively.     

Surface Defects Management by In Situ Etching with Methanol for Efficient Inverted Inorganic Perovskite Solar Cells

Inorganic perovskite solar cells (IPSCs) have developed rapidly due to their good thermal stability and the bandgap suitable for perovskite/silicon tandem solar cells. However, the large open-circuit voltage (V_OC) deficit derived from the surface defects and the energy level structure mismatch impede the development of device performance, especially in the P-I-N structure IPSCs. Herein, an innovative in situ etching (ISE) treatment method is proposed to reduce surface defects through methanol without additional passivator. It is found that the perovskite films treated with methanol result in a slight excess of PbI₂ on the surface and inserted into the grain boundaries. Therefore, the successful decrease of surface defects by methanol and the passivation of grain boundary defects by PbI₂ greatly reduce the trap density of perovskite films. And the larger work function of PbI₂ contributes to the energy band of perovskite surface bending downward and forms gradient energy level alignment at the I/N interface, which accelerates extraction of charge carriers. As a result, the efficiency of CsPbI_2.85Br_0.15 inverted IPSC is enhanced from 16.00% to 19.34%, which is one of the mostly efficient IPSCs. This work provides an original idea without additional passivator to manage the defects of inorganic perovskite.     

Fully Printed High-Performance Quasi-Two-Dimensional Perovskite Solar Cells via Multifunctional Interfacial Engineering

Planar n–i–p carbon perovskite solar cells (PSCs) with a hole transport layer that can be fabricated at low temperatures at low-cost exhibit great potential for large-scale manufacturing. Moreover, 2D perovskites have attracted considerable attention owing to their higher stability. In this work, scalable and highly efficient fully printed large-area carbon electrode-based 2D perovskite modules are reported through the insertion of a thin naphthaleneimide derivative (CATNI)-based interfacial layer between tin (IV) oxide and the perovskite layer. The results show that this facilitates the formation of the interfacial contact, suppresses energy losses, and substantially improves the performance parameters of the PSCs, especially their V_OC value. A significantly enhanced V_OC of 1.13 V is achieved resulting in the device PCE value reaching over 18%, which is one of the highest reported for fully printed PSCs so far. It is found that with the deployment of this CATNI-based interfacial layer, a more efficient carrier extraction is achieved. This ultimately contributed to enhanced spectral response as well as improved V_OC for these carbon electrodes based on fully printed devices. Finally, the carbon-perovskite solar modules (carbon-PSMs) are fabricated on ITO glass substrates with dimensions of 5.0 × 5.0 cm. These prepared modules exhibited outstanding photovoltaic performance with the highest PCE value of over 14.6%.     

Side-Chain Functionalized Polymer Hole-Transporting Materials with Defect Passivation Effect for Highly Efficient Inverted Quasi-2D Perovskite Solar Cells

Compared with inverted 3D perovskite solar cell (PSCs), inverted quasi-2D PSCs have advantages in device stability, but the device efficiency is still lagging behind. Constructing polymer hole-transporting materials (HTMs) with passivation functions to improve the buried interface and crystallization properties of perovskite films is one of the effective strategies to improve the performance of inverted quasi-2D PSCs. Herein, two novel side-chain functionalized polymer HTMs containing methylthio-based passivation groups are designed, named PVCz-SMeTPA and PVCz-SMeDAD, for inverted quasi-2D PSCs. Benefited from the non-conjugated flexible backbone bearing functionalized side-chain groups, the polymer HTMs exhibit excellent film-forming properties, well-matched energy levels and improved charge mobility, which facilitates the charge extraction and transport between HTM and quasi-2D perovskite layer. More importantly, by introducing methylthio units, the polymer HTMs can enhance the contact and interactions with quasi-2D perovskite, and further passivating the buried interface defects and assisting the deposition of high-quality perovskite. Due to the suppressed interfacial non-radiative recombination, the inverted quasi-2D PSCs using PVCz-SMeTPA and PVCz-SMeDAD achieve impressive power conversion efficiency (PCE) of 21.41% and 20.63% with open-circuit voltage of 1.23 and 1.22 V, respectively. Furthermore, the PVCz-SMeTPA based inverted quasi-2D PSCs also exhibits negligible hysteresis and considerably improved thermal and long-term stability.