Enhanced stability of P3HT poly crystalline Si thin film hybrid solar cells

Hybrid solar cells have been fabricated from solution processing of poly 3 hexylthiophen 2,5 diyl onto planar poly crystalline thin film silicon poly Si absorbers on glass. The poly Si layers were prepared by laser crystallization. Methyl passivation of the poly Si surface by a one step grafting process via methyl Grignard enabled open circuit voltages of up to 552mV and an overall power conversion efficiency of 6.6 for this device type. The solar cell exhibited significant advantages compared to the wafer based counterparts. The inverted device structure of the thin film cell lead to an enhancement of the quantum efficiency since the back side contacted cell had less light absorption and reflection losses due to the gold layer which was used as front contact for the c Si based hybrid solar cell. As a result, a photo current of 24.3 mA cm2 was obtained for a 10mm thin poly Si layer on glass. Furthermore, the inverted device structure showed a pronounced increase in stability due to the much thicker gold back contact that reduces the diffusion of water and oxygen toward the polymer layer. After 3 months in ambient air, this type of solar cell operated with 86 of its initial efficienc

Polythiophenes as emitter layers for crystalline silicon solar cells Parasitic absorption, interface passivation, and open circuit voltage

We investigated the influence of the emitter amorphous Si, a Si, or polythiophene derivatives poly 3 hexylthiophene , P3HT, and poly 3 [3,6 dioxaheptyl] thiophene , P3DOT and the interface passivation intrinsic a Si or SiOX and methyl groups or SiOX on the c Si based 1 amp; 8201; amp; 8201;1 amp; 8201;cm2 planar hybrid heterojunction solar cell parameters. We observed higher short circuit currents for the P3HT or P3DOT c Si solar cells than those obtained for a Si c Si devices, independent of the interface passivation. The obtained VOC of 659 amp; 8201;mV for the P3DOT SiOX c Si heterojunction solar cell with hydrophilic 3,6 dioxaheptyl side chains is among the highest reported for c Si polythiophene devices. The maximum power conversion efficiency, PCE, was 11 for the P3DOT SiOX c Si heterojunction solar cell. Additionally, our wafer lifetime measurements reveal a field effect passivation in the wafer induced by the polythiophenes when deposited on c S

Side chain engineering of poly thiophene and its impact on crystalline silicon based hybrid solar cells

The influence of ether groups in the side chain of spin coated regioregular polythiophene derivatives on the polymer layer formation and the hybrid solar cell properties were investigated using electrical, optical, and X ray diffraction experiments. The polymer layers are of high crystallinity but the polymer with 3 ether groups in the side chain P3TOT did not show any vibrational fine structure in the UV Vis spectrum. The presence of ether groups in the side chains leads to better adhesion resulting in thinner and more homogeneous polymer layers. This, in turn, enhances the electronic properties of the planar hybrid solar cell. We find that the power conversion efficiency increases with the number of ether groups in the side chains, and a maximum power conversion efficiency of 9.6 is achieved even in simple planar structures. amp; 8195

Adults with Philadelphia chromosome–like acute lymphoblastic leukemia frequently have IGH-CRLF2 and JAK2 mutations, persistence of minimal residual disease and poor prognosis

Philadelphia-like B-cell precursor acute lymphoblastic leukemia (Ph-like ALL) is characterized by distinct genetic alterations and inferior prognosis in children and younger adults. The purpose of this study was a genetic and clinical characterization of Ph-like ALL in adults. Twenty-six (13%) of 207 adult patients (median age: 42 years) with B-cell precursor ALL (BCP-ALL) were classified as having Ph-like ALL using gene expression profiling. The frequency of Ph-like ALL was 27% among 95 BCP-ALL patients negative for BCR-ABL1 and KMT2A-rearrangements. IGH-CRLF2 rearrangements (6/16; P=0.002) and mutations in JAK2 (7/16; P<0.001) were found exclusively in the Ph-like ALL subgroup. Clinical and outcome analyses were restricted to patients treated in German Multicenter Study Group for Adult ALL (GMALL) trials 06/99 and 07/03 (n=107). The complete remission rate was 100% among both Ph-like ALL patients (n=19) and the “remaining BCP-ALL” cases (n=40), i.e. patients negative for BCR-ABL1 and KMT2A-rearrangements and the Ph-like subtype. Significantly fewer Ph-like ALL patients reached molecular complete remission (33% versus 79%; P=0.02) and had a lower probability of continuous complete remission (26% versus 60%; P=0.03) and overall survival (22% versus 64%; P=0.006) at 5 years compared to the remaining BCP-ALL patients. The profile of genetic lesions in adults with Ph-like ALL, including older adults, resembles that of pediatric Ph-like ALL and differs from the profile in the remaining BCP-ALL. Our study is the first to demonstrate that Ph-like ALL is associated with inferior outcomes in intensively treated older adult patients. Ph-like adult ALL should be recognized as a distinct, high-risk entity and further research on improved diagnostic and therapeutic approaches is needed

Acute myeloid leukemia with biallelic CEBPA gene mutations and normal karyotype represents a distinct genetic entity associated with a favorable clinical outcome.

Purpose CEBPA mutations are found as either biallelic (biCEBPA) or monoallelic (moCEBPA). We set out to explore whether the kind of CEBPA mutation is of prognostic relevance in cytogenetically normal (CN) acute myeloid leukemia (AML). Patients and Methods: Four hundred sixty-seven homogeneously treated patients with CN-AML were subdivided into moCEBPA, biCEBPA, and wild-type (wt) CEBPA patients. The subgroups were analyzed for clinical parameters and for additional mutations in the NPM1, FLT3, and MLL genes. Furthermore, we obtained gene expression profiles using oligonucleotide microarrays. Results: Only patients with biCEBPA had an improved median overall survival when compared with patients with wtCEBPA (not reached v 20.4 months, respectively; P = .018), whereas patients with moCEBPA (20.9 months) and wtCEBPA had a similar outcome (P = .506). Multivariable analysis confirmed biCEBPA, but not moCEBPA, mutations as an independent favorable prognostic factor. Interestingly, biCEBPA mutations, compared with wtCEBPA, were never associated with mutated NPM1 (0% v 43%, respectively; P &lt; .001) and rarely associated with FLT3 internal tandem duplication (ITD; 5% v 23%, respectively; P = .059), whereas patients with moCEBPA had a similar frequency of mutated NPM1 and a significantly higher association with FLT3-ITD compared with patients with wtCEBPA (44% v 23%, respectively; P = .037). Furthermore, patients with biCEBPA showed a homogeneous gene expression profile that was characterized by downregulation of HOX genes, whereas patients with moCEBPA showed greater heterogeneity in their gene expression profiles. Conclusion: Biallelic disruption of the N and C terminus of CEBPA is required for the favorable clinical outcome of CEBPA-mutated patients and represents a distinct molecular subtype of CN-AML with a different frequency of associated gene mutations. These findings are of great significance for risk-adapted therapeutic strategies in AML

Acute myeloid leukemia with del(9q) is characterized by frequent mutations of <em>NPM1, DNMT3A, WT1</em> and low expression of <em>TLE4.</em>

Deletions of the long arm of chromosome 9 [del(9q)] are a rare but recurring aberration in acute myeloid leukemia (AML). Del(9q) can be found as the sole abnormality or in combination with other cytogenetic aberrations such as t(8;21) and t(15;17). TLE1 and TLE4 were identified to be critical genes contained in the 9q region. We performed whole exome sequencing of 5 patients with del(9q) as the sole abnormality followed by targeted amplicon sequencing of 137 genes of 26 patients with del(9q) as sole or combined with other aberrations. We detected frequent mutations in NPM1 (10/26; 38%), DNMT3A (8/26; 31%), and WT1 (8/26; 31%) but only few FLT3-ITDs (2/26; 8%). All mutations affecting NPM1 and DNMT3A were exclusively identified in patients with del(9q) as the sole abnormality and were significantly more frequent compared to 111 patients classified as intermediate-II according to the European LeukemiaNet (10/14, 71% vs. 22/111, 20%; P &lt; 0.001, 8/14, 57% vs. 26/111, 23%; P = 0.02). Furthermore, we identified DNMT3B to be rarely but recurrently targeted by truncating mutations in AML. Gene expression analysis of 13 patients with del(9q) and 454 patients with normal karyotype or various cytogenetic aberrations showed significant down regulation of TLE4 in patients with del(9q) (P = 0.02). Interestingly, downregulation of TLE4 was not limited to AML with del(9q), potentially representing a common mechanism in AML pathogenesis. Our comprehensive genetic analysis of the del(9q) subgroup reveals a unique mutational profile with the frequency of DNMT3A mutations in the del(9q) only subset being the highest reported so far in AML, indicating oncogenic cooperativity

The <em>NPM1</em> mutation type has no impact on survival in cytogenetically normal AML.

NPM1 mutations represent frequent genetic alterations in patients with acute myeloid leukemia (AML) associated with a favorable prognosis. Different types of NPM1 mutations have been described. The purpose of our study was to evaluate the relevance of different NPM1 mutation types with regard to clinical outcome. Our analyses were based on 349 NPM1-mutated AML patients treated in the AMLCG99 trial. Complete remission rates, overall survival and relapse-free survival were not significantly different between patients with NPM1 type A or rare type mutations. The NPM1 mutation type does not seem to play a role in risk stratification of cytogenetically normal AML