26.7% efficiency silicon heterojunction solar cells achieved by electrically optimized nanocrystalline-silicon hole contact layers

Abstract

Thanks to the prominent passivating contact structures, silicon heterojunction (SHJ) solar cell has recently achieved revolutionary advancements in the photovoltaic industry. This is, however, bound to further strengthen its contact performance for gaining the competitive edge in the period of technology transformation. Here, we developed SHJ cells with improved rear contact consisting of a p-type doped nanocrystalline silicon and a tailored transparent conductive oxide. Benefiting from the low contact resistance of hole-selective contacts (< 5 mΩ·cm2), a high power conversion efficiency of 26.74% together with a record filling factor (FF) of 86.48% were certified on industrial-grade silicon wafers (274 cm2, M6 size). The electrical properties of the modified SHJ cells were thoroughly analyzed in comparison with the normal p-type transporting layer counterparts (i.e., amorphous silicon), and the improved charge carrier transport in behind were also fully demonstrated.

Status report on emerging photovoltaics

“…Mainstream solar cell technology (or technologies) has developed rapidly in terms of efficiency 163 concomitant with a huge increase in scale; global PV installations in 2022 were above 250GW and year-on-year growth is expected for decades to come. However, the giant strides taken in silicon technology development mean that it is now approaching its efficiency limit—perovskite-silicon tandem technology opens up huge new possibilities for higher efficiency devices and have become the subject of intense academic and industrial interest.…”

Bicontinuous donor and acceptor fibril networks enable 19.2% efficiency pseudo‐bulk heterojunction organic solar cells

“…[ 9,10 ] However, due to the low dielectric constant and slow intermolecular charge transport in organic materials, [ 11–14 ] the PCEs of OSCs are still inferior compared with their inorganic counterparts such as Si‐ and GaAs‐based photovoltaics. [ 15,16 ]…”

“…organic materials, [11][12][13][14] the PCEs of OSCs are still inferior compared with their inorganic counterparts such as Si-and GaAs-based photovoltaics. [15,16] For aggregation control, received wisdom teaches that achieving fibrillar charge transport networks in the electron donor/acceptor mixed photoactive layer is crucial to obtain efficient exciton dissociation and charge collection toward record efficiency. [17][18][19][20] As discussed in previous works, [21][22][23][24] fibrillation refers to the self-assembly of materials growing in a specific direction to obtain one-dimensional structure and has been demonstrated to require different organization dynamics for materials with different structures.…”

Conductive passivating contact for high fill factor monolithic perovskite/silicon tandem solar cells

“…[3] Tremendous efforts have been tried to increase the efficiency of PK/Si TSCs, for example, by perovskite composition control, [4] interface passivation, processing method optimization, [5] recombination layer selection, [6][7][8] and so on, the open circuit voltage (V OC ) of PK/Si TSCs have reached up to 1.97 V which is close the limitation. [9] In addition, via device configuration design, [10,11] light management, [12][13][14][15] nano-optical designs, [16] and so on, the short-circuit current density (J SC ) of PK/Si TSCs has already been over 20 mA/cm 2 . Recently, PK/Si TSC has obtained a PCE of 33.7%, [9] confirming the significant potential of this technology.…”

“…In 1961, Shockley and Queisser proposed the theoretical limit of 29.4% (S‐Q limit) of single‐junction solar cells. [ 1 ] Until now, the highest power conversion efficiency (PCE) of 26.81% has been achieved by single‐junction silicon (Si) solar cells, [ 2 ] which is very close to the S‐Q limit. Therefore, further enhancing the PCE of single‐junction Si solar cells has become a big challenge.…”